diff --git a/core/types/l2trace.go b/core/types/l2trace.go
index 135d4542ba..70639d7434 100644
--- a/core/types/l2trace.go
+++ b/core/types/l2trace.go
@@ -32,17 +32,17 @@ type ExecutionResult struct {
 // StructLogRes stores a structured log emitted by the EVM while replaying a
 // transaction in debug mode
 type StructLogRes struct {
-	Pc            uint64             `json:"pc"`
-	Op            string             `json:"op"`
-	Gas           uint64             `json:"gas"`
-	GasCost       uint64             `json:"gasCost"`
-	Depth         int                `json:"depth"`
-	Error         string             `json:"error,omitempty"`
-	Stack         *[]string          `json:"stack,omitempty"`
-	Memory        *[]string          `json:"memory,omitempty"`
-	Storage       *map[string]string `json:"storage,omitempty"`
-	RefundCounter uint64             `json:"refund,omitempty"`
-	ExtraData     *ExtraData         `json:"extraData,omitempty"`
+	Pc            uint64            `json:"pc"`
+	Op            string            `json:"op"`
+	Gas           uint64            `json:"gas"`
+	GasCost       uint64            `json:"gasCost"`
+	Depth         int               `json:"depth"`
+	Error         string            `json:"error,omitempty"`
+	Stack         []string          `json:"stack,omitempty"`
+	Memory        []string          `json:"memory,omitempty"`
+	Storage       map[string]string `json:"storage,omitempty"`
+	RefundCounter uint64            `json:"refund,omitempty"`
+	ExtraData     *ExtraData        `json:"extraData,omitempty"`
 }
 
 type ExtraData struct {
diff --git a/core/vm/logger.go b/core/vm/logger.go
index d5c88bf39a..8d801f3876 100644
--- a/core/vm/logger.go
+++ b/core/vm/logger.go
@@ -441,11 +441,29 @@ func (t *mdLogger) CaptureEnter(typ OpCode, from common.Address, to common.Addre
 
 func (t *mdLogger) CaptureExit(output []byte, gasUsed uint64, err error) {}
 
+var (
+	formatPool = sync.Pool{
+		New: func() interface{} {
+			return make([]types.StructLogRes, 0, 128)
+		},
+	}
+)
+
 // FormatLogs formats EVM returned structured logs for json output
 func FormatLogs(logs []StructLog) []types.StructLogRes {
-	formatted := make([]types.StructLogRes, len(logs))
+	formatted := formatPool.Get().([]types.StructLogRes)
+	runtime.SetFinalizer(&formatted, func(format *[]types.StructLogRes) {
+		for _, res := range *format {
+			res.ExtraData = nil
+			res.Storage = nil
+			res.Stack = res.Stack[:0]
+			res.Memory = res.Memory[:0]
+		}
+		formatPool.Put(*format)
+	})
+
 	for index, trace := range logs {
-		formatted[index] = types.StructLogRes{
+		formatted = append(formatted, types.StructLogRes{
 			Pc:            trace.Pc,
 			Op:            trace.Op.String(),
 			Gas:           trace.Gas,
@@ -453,27 +471,29 @@ func FormatLogs(logs []StructLog) []types.StructLogRes {
 			Depth:         trace.Depth,
 			RefundCounter: trace.RefundCounter,
 			Error:         trace.ErrorString(),
-		}
+		})
 		if len(trace.Stack) != 0 {
-			stack := make([]string, len(trace.Stack))
-			for i, stackValue := range trace.Stack {
-				stack[i] = stackValue.Hex()
+			if formatted[index].Stack == nil {
+				formatted[index].Stack = make([]string, 0, len(trace.Stack))
+			}
+			for _, stackValue := range trace.Stack {
+				formatted[index].Stack = append(formatted[index].Stack, stackValue.Hex())
 			}
-			formatted[index].Stack = &stack
 		}
 		if trace.Memory.Len() != 0 {
-			memory := make([]string, 0, (trace.Memory.Len()+31)/32)
-			for i := 0; i+32 <= trace.Memory.Len(); i += 32 {
-				memory = append(memory, fmt.Sprintf("%x", trace.Memory.Bytes()[i:i+32]))
+			if formatted[index].Memory == nil {
+				formatted[index].Memory = make([]string, 0, (trace.Memory.Len()+31)/32)
+			}
+			for i := 0; i+32 <= trace.Memory.Len(); i += 32 {
+				formatted[index].Memory = append(formatted[index].Memory, common.Bytes2Hex(trace.Memory.Bytes()[i:i+32]))
 			}
-			formatted[index].Memory = &memory
 		}
 		if len(trace.Storage) != 0 {
 			storage := make(map[string]string)
 			for i, storageValue := range trace.Storage {
-				storage[fmt.Sprintf("%x", i)] = fmt.Sprintf("%x", storageValue)
+				storage[i.Hex()] = storageValue.Hex()
 			}
-			formatted[index].Storage = &storage
+			formatted[index].Storage = storage
 		}
 		if trace.ExtraData != nil {
 			formatted[index].ExtraData = trace.ExtraData.SealExtraData()
diff --git a/core/vm/logger_trace.go b/core/vm/logger_trace.go
index db100599ae..5b0eccfd90 100644
--- a/core/vm/logger_trace.go
+++ b/core/vm/logger_trace.go
@@ -161,12 +161,13 @@ func getWrappedProofForStorage(l *StructLogger, address common.Address, key comm
 	}, nil
 }
 
-func encodeProof(proof [][]byte) (res []string) {
+func encodeProof(proof [][]byte) []string {
 	if len(proof) == 0 {
 		return nil
 	}
+	res := make([]string, 0, len(proof))
 	for _, node := range proof {
 		res = append(res, hexutil.Encode(node))
 	}
-	return
+	return res
 }