diff --git a/index.d.ts b/index.d.ts
index e271145..9bc0126 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -1,4 +1,4 @@
-declare module '@onekeyfe/kaspacore-lib' {
+declare module '@onekeyfe/kaspa-core-lib' {
 
 	function initRuntime(): Promise;
 	function setDebugLevel(level:number):void;
diff --git a/lib/transaction/transaction.js b/lib/transaction/transaction.js
index 9e60a9e..cbf676a 100644
--- a/lib/transaction/transaction.js
+++ b/lib/transaction/transaction.js
@@ -141,12 +141,12 @@ var ioProperty = {
 	configurable: false,
 	enumerable: true,
 	get: function() {
-		return this._getInputAmount();
+		return this._getInputAmount().toString();
 	}
 };
 Object.defineProperty(Transaction.prototype, 'inputAmount', ioProperty);
 ioProperty.get = function() {
-	return this._getOutputAmount();
+	return this._getOutputAmount().toString();
 };
 Object.defineProperty(Transaction.prototype, 'outputAmount', ioProperty);
 
@@ -226,7 +226,7 @@ Transaction.prototype.getSerializationError = function(opts) {
 
 	var unspent = this._getUnspentValue();
 	var unspentError;
-	if (unspent < 0) {
+	if (unspent.lt(0)) {
 		if (!opts.disableMoreOutputThanInput) {
 			unspentError = new errors.Transaction.InvalidOutputAmountSum();
 		}
@@ -931,36 +931,34 @@ Transaction.prototype._addOutput = function(output) {
 /**
  * Calculates or gets the total output amount in satoshis
  *
- * @return {Number} the transaction total output amount
+ * @return {BN} the transaction total output amount
  */
 Transaction.prototype._getOutputAmount = function() {
 	if (_.isUndefined(this._outputAmount)) {
-		var self = this;
-		this._outputAmount = 0;
-		_.each(this.outputs, function(output) {
-			self._outputAmount += output.satoshis;
-		});
+	  this._outputAmount = this.outputs.reduce((sum, output) => {
+		return sum.add(new BN(output.satoshis));
+	  }, new BN(0));
 	}
 	return this._outputAmount;
-};
+  };
 
 
 /**
  * Calculates or gets the total input amount in satoshis
  *
- * @return {Number} the transaction total input amount
+ * @return {BN} the transaction total input amount
  */
 Transaction.prototype._getInputAmount = function() {
 	if (_.isUndefined(this._inputAmount)) {
-		this._inputAmount = _.sumBy(this.inputs, function(input) {
-			if (_.isUndefined(input.output)) {
-				throw new errors.Transaction.Input.MissingPreviousOutput();
-			}
-			return input.output.satoshis;
-		});
+	  this._inputAmount = this.inputs.reduce((sum, input) => {
+		if (_.isUndefined(input.output)) {
+		  throw new errors.Transaction.Input.MissingPreviousOutput();
+		}
+		return sum.add(new BN(input.output.satoshis));
+	  }, new BN(0));
 	}
 	return this._inputAmount;
-};
+  };
 
 Transaction.prototype._updateChangeOutput = function() {
 	if (!this._changeScript) {
@@ -972,8 +970,8 @@ Transaction.prototype._updateChangeOutput = function() {
 	}
 	var available = this._getUnspentValue();
 	var fee = this.getFee();
-	var changeAmount = available - fee;
-	if (changeAmount > 0) {
+	var changeAmount = available.sub(fee);
+	if (changeAmount.gt(0)) {
 		this._changeIndex = this.outputs.length;
 		this._addOutput(new Output({
 			script: this._changeScript,
@@ -1010,7 +1008,7 @@ Transaction.prototype.getFee = function() {
 	}
 	// if no change output is set, fees should equal all the unspent amount
 	if (!this._changeScript) {
-		return this._getUnspentValue();
+		return this._getUnspentValue().toNumber();
 	}
 	return this._estimateFee();
 };
@@ -1028,14 +1026,14 @@ Transaction.prototype._estimateFee = function() {
 	}
 	var fee = Math.ceil(getFee(estimatedSize));
 	var feeWithChange = Math.ceil(getFee(estimatedSize) + getFee(Transaction.CHANGE_OUTPUT_MAX_SIZE));
-	if (!this._changeScript || available <= feeWithChange) {
+	if (!this._changeScript || available.lte(feeWithChange)) {
 		return fee;
 	}
 	return feeWithChange;
 };
 
 Transaction.prototype._getUnspentValue = function() {
-	return this._getInputAmount() - this._getOutputAmount();
+	return this._getInputAmount().sub(this._getOutputAmount());
 };
 
 Transaction.prototype._clearSignatures = function() {
diff --git a/package.json b/package.json
index cc0d83a..1d41829 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
-  "name": "@onekeyfe/kaspacore-lib",
-  "version": "1.0.0-alpha.5",
+  "name": "@onekeyfe/kaspa-core-lib",
+  "version": "1.0.0-alpha.2",
   "main": "index.js",
   "authors": [
     {