diff --git a/pkg/rpc/client/rpc_test.go b/pkg/rpc/client/rpc_test.go
index 36e78695d..8d55e2d3e 100644
--- a/pkg/rpc/client/rpc_test.go
+++ b/pkg/rpc/client/rpc_test.go
@@ -566,7 +566,7 @@ var rpcClientTestCases = map[string][]rpcClientTestCase{
 					},
 				})
 			},
-			serverResponse: `{"jsonrpc":"2.0","id":1,"result":{"script":"1426ae7c6c9861ec418468c1f0fdc4a7f2963eb89151c10962616c616e63654f6667be39e7b562f60cbfe2aebca375a2e5ee28737caf","state":"HALT","gas_consumed":"0.311","stack":[{"type":"ByteArray","value":"262bec084432"}],"tx":"d101361426ae7c6c9861ec418468c1f0fdc4a7f2963eb89151c10962616c616e63654f6667be39e7b562f60cbfe2aebca375a2e5ee28737caf000000000000000000000000"}}`,
+			serverResponse: `{"jsonrpc":"2.0","id":1,"result":{"script":"1426ae7c6c9861ec418468c1f0fdc4a7f2963eb89151c10962616c616e63654f6667be39e7b562f60cbfe2aebca375a2e5ee28737caf","state":"HALT","gas_consumed":"0.311","stack":[{"type":"ByteArray","value":"JivsCEQy"}],"tx":"d101361426ae7c6c9861ec418468c1f0fdc4a7f2963eb89151c10962616c616e63654f6667be39e7b562f60cbfe2aebca375a2e5ee28737caf000000000000000000000000"}}`,
 			result: func(c *Client) interface{} {
 				bytes, err := hex.DecodeString("262bec084432")
 				if err != nil {
@@ -592,7 +592,7 @@ var rpcClientTestCases = map[string][]rpcClientTestCase{
 			invoke: func(c *Client) (interface{}, error) {
 				return c.InvokeScript("00046e616d656724058e5e1b6008847cd662728549088a9ee82191")
 			},
-			serverResponse: `{"jsonrpc":"2.0","id":1,"result":{"script":"00046e616d656724058e5e1b6008847cd662728549088a9ee82191","state":"HALT","gas_consumed":"0.161","stack":[{"type":"ByteArray","value":"4e45503520474153"}],"tx":"d1011b00046e616d656724058e5e1b6008847cd662728549088a9ee82191000000000000000000000000"}}`,
+			serverResponse: `{"jsonrpc":"2.0","id":1,"result":{"script":"00046e616d656724058e5e1b6008847cd662728549088a9ee82191","state":"HALT","gas_consumed":"0.161","stack":[{"type":"ByteArray","value":"TkVQNSBHQVM="}],"tx":"d1011b00046e616d656724058e5e1b6008847cd662728549088a9ee82191000000000000000000000000"}}`,
 			result: func(c *Client) interface{} {
 				bytes, err := hex.DecodeString("4e45503520474153")
 				if err != nil {
diff --git a/pkg/rpc/client/wsclient_test.go b/pkg/rpc/client/wsclient_test.go
index b3d88e528..e6c053f94 100644
--- a/pkg/rpc/client/wsclient_test.go
+++ b/pkg/rpc/client/wsclient_test.go
@@ -115,8 +115,8 @@ func TestWSClientEvents(t *testing.T) {
 	var ok bool
 	// Events from RPC server test chain.
 	var events = []string{
-		`{"jsonrpc":"2.0","method":"transaction_executed","params":[{"txid":"0xe1cd5e57e721d2a2e05fb1f08721b12057b25ab1dd7fd0f33ee1639932fdfad7","executions":[{"trigger":"Application","contract":"0x0000000000000000000000000000000000000000","vmstate":"HALT","gas_consumed":"2.291","stack":[],"notifications":[{"contract":"0x1b4357bff5a01bdf2a6581247cf9ed1e24629176","state":{"type":"Array","value":[{"type":"ByteArray","value":"636f6e74726163742063616c6c"},{"type":"ByteArray","value":"7472616e73666572"},{"type":"Array","value":[{"type":"ByteArray","value":"769162241eedf97c2481652adf1ba0f5bf57431b"},{"type":"ByteArray","value":"316e851039019d39dfc2c37d6c3fee19fd580987"},{"type":"Integer","value":"1000"}]}]}},{"contract":"0x1b4357bff5a01bdf2a6581247cf9ed1e24629176","state":{"type":"Array","value":[{"type":"ByteArray","value":"7472616e73666572"},{"type":"ByteArray","value":"769162241eedf97c2481652adf1ba0f5bf57431b"},{"type":"ByteArray","value":"316e851039019d39dfc2c37d6c3fee19fd580987"},{"type":"Integer","value":"1000"}]}}]}]}]}`,
-		`{"jsonrpc":"2.0","method":"notification_from_execution","params":[{"contract":"0x1b4357bff5a01bdf2a6581247cf9ed1e24629176","state":{"type":"Array","value":[{"type":"ByteArray","value":"636f6e74726163742063616c6c"},{"type":"ByteArray","value":"7472616e73666572"},{"type":"Array","value":[{"type":"ByteArray","value":"769162241eedf97c2481652adf1ba0f5bf57431b"},{"type":"ByteArray","value":"316e851039019d39dfc2c37d6c3fee19fd580987"},{"type":"Integer","value":"1000"}]}]}}]}`,
+		`{"jsonrpc":"2.0","method":"transaction_executed","params":[{"txid":"0xe1cd5e57e721d2a2e05fb1f08721b12057b25ab1dd7fd0f33ee1639932fdfad7","executions":[{"trigger":"Application","contract":"0x0000000000000000000000000000000000000000","vmstate":"HALT","gas_consumed":"2.291","stack":[],"notifications":[{"contract":"0x1b4357bff5a01bdf2a6581247cf9ed1e24629176","state":{"type":"Array","value":[{"type":"ByteArray","value":"Y29udHJhY3QgY2FsbA=="},{"type":"ByteArray","value":"dHJhbnNmZXI="},{"type":"Array","value":[{"type":"ByteArray","value":"dpFiJB7t+XwkgWUq3xug9b9XQxs="},{"type":"ByteArray","value":"MW6FEDkBnTnfwsN9bD/uGf1YCYc="},{"type":"Integer","value":"1000"}]}]}},{"contract":"0x1b4357bff5a01bdf2a6581247cf9ed1e24629176","state":{"type":"Array","value":[{"type":"ByteArray","value":"dHJhbnNmZXI="},{"type":"ByteArray","value":"dpFiJB7t+XwkgWUq3xug9b9XQxs="},{"type":"ByteArray","value":"MW6FEDkBnTnfwsN9bD/uGf1YCYc="},{"type":"Integer","value":"1000"}]}}]}]}]}`,
+		`{"jsonrpc":"2.0","method":"notification_from_execution","params":[{"contract":"0x1b4357bff5a01bdf2a6581247cf9ed1e24629176","state":{"type":"Array","value":[{"type":"ByteArray","value":"Y29udHJhY3QgY2FsbA=="},{"type":"ByteArray","value":"dHJhbnNmZXI="},{"type":"Array","value":[{"type":"ByteArray","value":"dpFiJB7t+XwkgWUq3xug9b9XQxs="},{"type":"ByteArray","value":"MW6FEDkBnTnfwsN9bD/uGf1YCYc="},{"type":"Integer","value":"1000"}]}]}}]}`,
 		`{"jsonrpc":"2.0","method":"transaction_added","params":[{"txid":"0x1c615d4043c98fc0e285c2f40cc3601cf4ebe1cf9d2b404dfc67c9cd085444ec","size":265,"version":0,"nonce":9,"sender":"ALHF9wsXZVEuCGgmDA6ZNsCLtrb4A1g4yG","sys_fee":"0","net_fee":"0.0036521","valid_until_block":1200,"attributes":[],"cosigners":[{"account":"0x870958fd19ee3f6c7dc3c2df399d013910856e31","scopes":1}],"script":"007b0c1420728274afafc36f43a071d328cfa3e629d9cbb00c14316e851039019d39dfc2c37d6c3fee19fd58098713c00c087472616e736665720c14769162241eedf97c2481652adf1ba0f5bf57431b41627d5b5238","scripts":[{"invocation":"DEA00C87l6Ig/+eWQOSCuIfsDkTcyV5xn14rQ7KZh/DJgiua8EmdkAlMatO6GR5DSj313TeNO3MxjPR8ny1tgBzI","verification":"DCECs2Ir9AF73+MXxYrtX0x1PyBrfbiWBG+n13S7xL9/jcILQQqQatQ="}]}]}`,
 		`{"jsonrpc":"2.0","method":"block_added","params":[{"hash":"0x765ea65b4de6addfee29b1c90ac922d1901c8d7ab7f2366da9a8ad3dd71ca703","version":0,"previousblockhash":"0xbdeed527a43ab72d5d8cecf1dc6ee142112ff8a8eaaaebc7206d3df3bf3c1169","merkleroot":"0xa1b321f59b127cddd23b0cd47fc9ec7920647d30d7ab23318a106597b9c9abad","time":1591366176006,"index":6,"nextconsensus":"AXSvJVzydxXuL9da4GVwK25zdesCrVKkHL","witnesses":[{"invocation":"DEDaH0tUaopg6WWWNRI013CTkYZrs1kKKQEzvAxFg38drGNR7jJQan4Lv2/LzD7AEiLM/oS8HUBxIh9MQy6/VptiDEDuWQYygBKopKQR5/ojqouiH+24GxFYHloofK2WH6NtKiCyBpVJpaFIYNnprjZA6iD5GR1gq3wq7d9D7dbavlWMDED1OR5559YvfMqpAFEdUw+J3hg/pRvEr3RL2oH3Y+FN3X+5U+abCQFmDUdS8kDVJpNE0LZLULEk0aMWrXJIbaFeDEABL3c/rvKu5K9Z4IO0Q+vmz0BNEvSdMpZsX0jywgPihEKWFaotNMgnNW1Vw74WEvZ6W3Jfb/Sbm5Wx9gMGpytx","verification":"EwwhAhA6f33QFlWFl/eWDSfFFqQ5T9loueZRVetLAT5AQEBuDCECp7xV/oaE4BGXaNEEujB5W9zIZhnoZK3SYVZyPtGFzWIMIQKzYiv0AXvf4xfFiu1fTHU/IGt9uJYEb6fXdLvEv3+NwgwhA9kMB99j5pDOd5EuEKtRrMlEtmhgI3tgjE+PgwnnHuaZFAtBMHOzuw=="}],"consensus_data":{"primary":0,"nonce":"0000000000000457"},"tx":[{"txid":"0x1c615d4043c98fc0e285c2f40cc3601cf4ebe1cf9d2b404dfc67c9cd085444ec","size":265,"version":0,"nonce":9,"sender":"ALHF9wsXZVEuCGgmDA6ZNsCLtrb4A1g4yG","sys_fee":"0","net_fee":"0.0036521","valid_until_block":1200,"attributes":[],"cosigners":[{"account":"0x870958fd19ee3f6c7dc3c2df399d013910856e31","scopes":1}],"script":"007b0c1420728274afafc36f43a071d328cfa3e629d9cbb00c14316e851039019d39dfc2c37d6c3fee19fd58098713c00c087472616e736665720c14769162241eedf97c2481652adf1ba0f5bf57431b41627d5b5238","scripts":[{"invocation":"DEA00C87l6Ig/+eWQOSCuIfsDkTcyV5xn14rQ7KZh/DJgiua8EmdkAlMatO6GR5DSj313TeNO3MxjPR8ny1tgBzI","verification":"DCECs2Ir9AF73+MXxYrtX0x1PyBrfbiWBG+n13S7xL9/jcILQQqQatQ="}]}]}]}`,
 		`{"jsonrpc":"2.0","method":"event_missed","params":[]}`,
diff --git a/pkg/smartcontract/parameter.go b/pkg/smartcontract/parameter.go
index 54eb394a5..303d47af8 100644
--- a/pkg/smartcontract/parameter.go
+++ b/pkg/smartcontract/parameter.go
@@ -1,6 +1,7 @@
 package smartcontract
 
 import (
+	"encoding/base64"
 	"encoding/binary"
 	"encoding/hex"
 	"encoding/json"
@@ -76,8 +77,10 @@ func (p *Parameter) MarshalJSON() ([]byte, error) {
 	case PublicKeyType, ByteArrayType, SignatureType:
 		if p.Value == nil {
 			resultRawValue = []byte("null")
-		} else {
+		} else if p.Type == PublicKeyType {
 			resultRawValue, resultErr = json.Marshal(hex.EncodeToString(p.Value.([]byte)))
+		} else {
+			resultRawValue, resultErr = json.Marshal(base64.StdEncoding.EncodeToString(p.Value.([]byte)))
 		}
 	case ArrayType:
 		var value = p.Value.([]Parameter)
@@ -121,7 +124,12 @@ func (p *Parameter) UnmarshalJSON(data []byte) (err error) {
 		if err = json.Unmarshal(r.Value, &s); err != nil {
 			return
 		}
-		if b, err = hex.DecodeString(s); err != nil {
+		if r.Type == PublicKeyType {
+			b, err = hex.DecodeString(s)
+		} else {
+			b, err = base64.StdEncoding.DecodeString(s)
+		}
+		if err != nil {
 			return
 		}
 		p.Value = b
diff --git a/pkg/smartcontract/parameter_test.go b/pkg/smartcontract/parameter_test.go
index 72ce299a4..a10a127a7 100644
--- a/pkg/smartcontract/parameter_test.go
+++ b/pkg/smartcontract/parameter_test.go
@@ -1,6 +1,8 @@
 package smartcontract
 
 import (
+	"encoding/base64"
+	"encoding/hex"
 	"encoding/json"
 	"math"
 	"reflect"
@@ -30,7 +32,7 @@ var marshalJSONTestCases = []struct {
 	},
 	{
 		input:  Parameter{Type: ByteArrayType, Value: []byte{0x01, 0x02, 0x03}},
-		result: `{"type":"ByteArray","value":"010203"}`,
+		result: `{"type":"ByteArray","value":"` + hexToBase64("010203") + `"}`,
 	},
 	{
 		input:  Parameter{Type: ByteArrayType},
@@ -66,8 +68,8 @@ var marshalJSONTestCases = []struct {
 					}},
 			},
 		},
-		result: `{"type":"Array","value":[{"type":"ByteArray","value":"0102"},{"type":"Array","value":[` +
-			`{"type":"ByteArray","value":"030201"},{"type":"ByteArray","value":"070809"}]}]}`,
+		result: `{"type":"Array","value":[{"type":"ByteArray","value":"` + hexToBase64("0102") + `"},{"type":"Array","value":[` +
+			`{"type":"ByteArray","value":"` + hexToBase64("030201") + `"},{"type":"ByteArray","value":"` + hexToBase64("070809") + `"}]}]}`,
 	},
 	{
 		input: Parameter{
@@ -176,7 +178,7 @@ var unmarshalJSONTestCases = []struct {
 		result: Parameter{Type: IntegerType, Value: int64(12345)},
 	},
 	{
-		input:  `{"type":"ByteArray","value":"010203"}`,
+		input:  `{"type":"ByteArray","value":"` + hexToBase64("010203") + `"}`,
 		result: Parameter{Type: ByteArrayType, Value: []byte{0x01, 0x02, 0x03}},
 	},
 	{
@@ -281,7 +283,7 @@ var unmarshalJSONTestCases = []struct {
 var unmarshalJSONErrorCases = []string{
 	`{"type": "ByteArray","value":`,        // incorrect JSON
 	`{"type": "ByteArray","value":1}`,      // incorrect Value
-	`{"type": "ByteArray","value":"12zz"}`, // incorrect ByteArray value
+	`{"type": "ByteArray","value":"12^"}`,  // incorrect ByteArray value
 	`{"type": "String","value":`,           // incorrect JSON
 	`{"type": "String","value":1}`,         // incorrect Value
 	`{"type": "Integer","value": "nn"}`,    // incorrect Integer value
@@ -497,3 +499,8 @@ func TestEncodeDecodeBinary(t *testing.T) {
 		require.Error(t, testserdes.DecodeBinary([]byte{0xAA}, &p))
 	})
 }
+
+func hexToBase64(s string) string {
+	b, _ := hex.DecodeString(s)
+	return base64.StdEncoding.EncodeToString(b)
+}