diff --git a/index.d.ts b/index.d.ts
index 2d0e50f..e271145 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -93,7 +93,7 @@ declare module '@onekeyfe/kaspacore-lib' {
 	export namespace Transaction {
 
 		static class sighash {
-			static sign(transaction, privateKey, sighashType, inputIndex, subscript, satoshisBN, flags, signingMethod);
+			// static sign(transaction, privateKey, sighashType, inputIndex, subscript, satoshisBN, flags, signingMethod);
 			static sighash(transaction, sighashType, inputNumber, subscript, satoshisBN, flags): Buffer;
 		}
 		class UnspentOutput {
@@ -155,7 +155,7 @@ declare module '@onekeyfe/kaspacore-lib' {
 		fee(amount: number): this;
 		setVersion(version: number): this;
 		feePerKb(amount: number): this;
-		sign(privateKey: PrivateKey|PrivateKey[] | string|string[], sigtype:number, signingMethod:string|undefined): this;
+		// sign(privateKey: PrivateKey|PrivateKey[] | string|string[], sigtype:number, signingMethod:string|undefined): this;
 		applySignature(sig: crypto.Signature): this;
 		addInput(input: Transaction.Input): this;
 		addOutput(output: Transaction.Output): this;
diff --git a/lib/transaction/output.js b/lib/transaction/output.js
index 8b7e9b6..55ab77f 100644
--- a/lib/transaction/output.js
+++ b/lib/transaction/output.js
@@ -160,7 +160,7 @@ Output.prototype.inspect = function() {
 
 Output.fromBufferReader = function(br) {
     var obj = {};
-    obj.satoshis = BN.fromNumber(br.readUInt64LEBN()).toString();
+    obj.satoshis = br.readUInt64LEBN().toString();
     var version = br.readUInt16LE();
     var size = br.readUInt64LEBN().toNumber();
     if (size !== 0) {
diff --git a/lib/transaction/sighash.js b/lib/transaction/sighash.js
index 2f90ee7..34d1979 100644
--- a/lib/transaction/sighash.js
+++ b/lib/transaction/sighash.js
@@ -529,6 +529,6 @@ function verify(transaction, signature, publicKey, inputIndex, subscript, satosh
  */
 module.exports = {
 	sighash: sighash,
-	sign: sign,
-	verify: verify
+	// sign: sign,
+	// verify: verify
 };
\ No newline at end of file
diff --git a/lib/transaction/unspentoutput.js b/lib/transaction/unspentoutput.js
index 933cb17..e142cad 100644
--- a/lib/transaction/unspentoutput.js
+++ b/lib/transaction/unspentoutput.js
@@ -7,6 +7,7 @@ var JSUtil = require('../util/js');
 var Script = require('../script');
 var Address = require('../address');
 var Unit = require('../unit');
+var BN = require('../crypto/bn');
 
 /**
  * Represents an unspent output information: its script, associated amount and address,
@@ -46,8 +47,16 @@ function UnspentOutput(data) {
   var script = new Script(data.scriptPubKey || data.script);
   $.checkArgument(!_.isUndefined(data.amount) || !_.isUndefined(data.satoshis),
                   'Must provide an amount for the output');
-  var amount = !_.isUndefined(data.amount) ? new Unit.fromBTC(data.amount).toSatoshis() : data.satoshis;
-  $.checkArgument(_.isNumber(amount), 'Amount must be a number');
+
+  var amount;
+  if (!_.isUndefined(data.amount)) {
+    amount = BN.fromNumber(data.amount);
+    amount = amount.mul(new BN(1e8)).toString();
+  } else {
+    amount = BN.fromNumber(data.satoshis).toString();
+  }
+  $.checkArgument(!amount.isNaN() && amount.gte(0) && amount.includes('.'), 'Amount must be a number');
+
   JSUtil.defineImmutable(this, {
     address: address,
     txId: txId,
diff --git a/lib/util/js.js b/lib/util/js.js
index af9395c..316f3e3 100644
--- a/lib/util/js.js
+++ b/lib/util/js.js
@@ -3,6 +3,8 @@
 var _ = require('lodash');
 var logLevels = require('./log').logLevels;
 
+const UINT64_MAX = new BN('18446744073709551615');
+
 /**
  * Determines whether a string contains only hexadecimal values
  *
@@ -85,10 +87,22 @@ const JSUtil = {
      * @return {Boolean}
      */
     isNaturalNumber: function isNaturalNumber(value) {
-        return typeof value === 'number' &&
-            isFinite(value) &&
-            Math.floor(value) === value &&
-            value >= 0;
+        if (typeof value === 'string') {
+            if (!/^\d*$/.test(value)) {
+                return false;
+            }
+        }
+
+        if(typeof value === 'number' || typeof value === 'string'){
+            try {
+                var bnValue = BN.fromNumber(value);
+                return bnValue.lte(UINT64_MAX);
+            } catch (e) {
+                return false;
+            }
+        }
+
+        return false;
     }
 };
 
diff --git a/package.json b/package.json
index 0f0a0aa..c6a6b0c 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@onekeyfe/kaspacore-lib",
-  "version": "1.0.0-alpha.1",
+  "version": "1.0.0-alpha.3",
   "main": "index.js",
   "authors": [
     {