diff --git a/frontend/mock/data/plugin/histograms/tags.js b/frontend/mock/data/plugin/histograms/tags.js
index 8a7cad30028ea22b3b1b79ce1bbda3da9d286a8e..71c747f7914b21b8e72c6ee3165c84d9c7752a0e 100644
--- a/frontend/mock/data/plugin/histograms/tags.js
+++ b/frontend/mock/data/plugin/histograms/tags.js
@@ -22,6 +22,11 @@ module.exports = function (path, queryParam, postParam) {
                     {
                         "displayName": "layer1/Wx_plus_b/pre_activations",
                         "description": ""
+                    },
+                    "layer1/Wx_plus_b/pre_activations_1":
+                    {
+                        "displayName": "layer1/Wx_plus_b/pre_activations_1",
+                        "description": ""
                     }
                 }
             }
diff --git a/frontend/src/histogram/ui/chart.san b/frontend/src/histogram/ui/chart.san
index 0c22e59a3ee6191563c9cf034e62a30127dcb57f..d6573c73e4d1bb1f85723c0ec0524908d256642b 100644
--- a/frontend/src/histogram/ui/chart.san
+++ b/frontend/src/histogram/ui/chart.san
@@ -24,6 +24,7 @@ import {format, precisionRound} from 'd3-format';
 import {getPluginHistogramsHistograms} from '../../service';
 
 let zrDrawElement = {};
+zrDrawElement.hoverDots = [];
 // the time to refresh chart data
 const intervalTime = 15;
 
@@ -152,6 +153,9 @@ export default {
             },
             yAxis: {
                 type: 'value',
+                axisLine: {
+                    onZero: false
+                },
                 axisLabel: {
                     formatter(value, index) {
                         return yValueFormat(value);
@@ -224,6 +228,11 @@ export default {
                 axisLine: {
                     onZero: false
                 },
+                axisLabel: {
+                    formatter: function (value) {
+                        return Math.round(value * 100) / 100;
+                    }
+                },
                 splitLine: {
                     show: false
                 }
@@ -283,8 +292,6 @@ export default {
             return pt;
         }
 
-        zrDrawElement.hoverDots = [];
-
         let zr = ecChart.getZr();
 
         function removeTooltip() {
@@ -361,7 +368,7 @@ export default {
                 zrDrawElement.tooltip = new echarts.graphic.Text({
                     position: [e.offsetX + 30, e.offsetY - 50],
                     style: {
-                        text: hoveredItem.items[nearestIndex.binIndex][3],
+                        text: yValueFormat(hoveredItem.items[nearestIndex.binIndex][3]),
                         textFill: '#000',
                         fontSize: 14,
                         textBackgroundColor: '#eee',