diff --git a/src/chart/map.js b/src/chart/map.js
index 6a4628f037..57ba8a811e 100644
--- a/src/chart/map.js
+++ b/src/chart/map.js
@@ -34,7 +34,7 @@ define(function (require) {
         //},
         // mapValueCalculation: 'sum',  // 数值合并方式，默认加和，可选为：
                                         // 'sum' | 'average' | 'max' | 'min'
-        mapValuePrecision: 0,           // 地图数值计算结果小数精度
+        // mapValuePrecision: 0,           // 地图数值计算结果小数精度
         showLegendSymbol: true,         // 显示图例颜色标识（系列标识的小圆点），存在legend时生效
         // selectedMode: false,         // 选择模式，默认关闭，可选single，multiple
         dataRangeHoverLink: true,
@@ -233,7 +233,8 @@ define(function (require) {
                             valueData[mapType][name] = valueData[mapType][name]
                                                        || {
                                                            seriesIndex : [],
-                                                           valueMap: {}
+                                                           valueMap: {},
+                                                           precision: 0
                                                        };
                             for (var key in data[j]) {
                                 if (key != 'value') {
@@ -245,6 +246,12 @@ define(function (require) {
                                     valueData[mapType][name].value == null
                                     && (valueData[mapType][name].value = 0);
 
+                                    valueData[mapType][name].precision = 
+                                        Math.max(
+                                            this.getPrecision(+data[j].value),
+                                            valueData[mapType][name].precision
+                                        );
+
                                     valueData[mapType][name].value += (+data[j].value);
                                     valueData[mapType][name].valueMap[i] = +data[j].value;
                                 }
@@ -268,14 +275,14 @@ define(function (require) {
                 this.lastShapeList = [];
             }
             for (var mt in valueData) {
-                if (valueCalculation[mt] && valueCalculation[mt] == 'average') {
-                    for (var k in valueData[mt]) {
-                        valueData[mt][k].value =
-                            (valueData[mt][k].value / valueData[mt][k].seriesIndex.length)
-                            .toFixed(
-                                mapValuePrecision[mt]
-                            ) - 0;
+                for (var k in valueData[mt]) {
+                    if (valueCalculation[mt] == 'average') {
+                        valueData[mt][k].value /= valueData[mt][k].seriesIndex.length;
                     }
+                    valueData[mt][k].value = valueData[mt][k].value.toFixed(
+                        mapValuePrecision[mt] == null
+                            ? valueData[mt][k].precision : mapValuePrecision[mt]
+                    ) - 0;
                 }
 
                 this._mapDataMap[mt] = this._mapDataMap[mt] || {};
diff --git a/src/component/base.js b/src/component/base.js
index d9ebd96ef5..1af8faad91 100644
--- a/src/component/base.js
+++ b/src/component/base.js
@@ -236,7 +236,9 @@ define(function (require) {
         parsePercent: number.parsePercent,
         parseCenter: number.parseCenter,
         parseRadius: number.parseRadius,
-        numAddCommas: number.addCommas
+        numAddCommas: number.addCommas,
+
+        getPrecision: number.getPrecision
     };
     
     return Base;
diff --git a/src/util/number.js b/src/util/number.js
index 824a6ba7b9..aacc02816c 100644
--- a/src/util/number.js
+++ b/src/util/number.js
@@ -61,11 +61,31 @@ define(function() {
         return x[0].replace(/(\d{1,3})(?=(?:\d{3})+(?!\d))/g,'$1,') 
                + (x.length > 1 ? ('.' + x[1]) : '');
     }
+
+    /**
+     * 获取数字的小数位数
+     * @param {number} val
+     */
+    
+    // It is much faster than methods converting number to string as follows 
+    //      var tmp = val.toString();
+    //      return tmp.length - 1 - tmp.indexOf('.');
+    // especially when precision is low
+    function getPrecision(val) {
+        var e = 1;
+        var count = 0;
+        while (((val * e) | 0) / e !== val) {
+            e *= 10;
+            count++;
+        }
+        return count;
+    }
     
     return {
-        parsePercent : parsePercent,
-        parseCenter : parseCenter,
-        parseRadius : parseRadius,
-        addCommas : addCommas
+        parsePercent: parsePercent,
+        parseCenter: parseCenter,
+        parseRadius: parseRadius,
+        addCommas: addCommas,
+        getPrecision: getPrecision
     };
 });
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