diff --git a/Assets/XCharts/CHANGELOG-EN.md b/Assets/XCharts/CHANGELOG-EN.md
index 055bdc75..b66dd70a 100644
--- a/Assets/XCharts/CHANGELOG-EN.md
+++ b/Assets/XCharts/CHANGELOG-EN.md
@@ -1,6 +1,7 @@
 
 # 更新日志
 
+* (2020.10.22) Improve the support of `VisualMap` for `Piecewise` in `HeatmapChart`
 * (2020.09.22) Fixed `PieChart` inconsistent border size
 * (2020.09.18) Added `Remove All Chart Object` to Remove All child nodes under the Chart (automatically reinitialized)
 * (2020.09.18) Fixed `SerieLabel` also displayed after hided `Serie` by clicked the legend #94
diff --git a/Assets/XCharts/CHANGELOG.md b/Assets/XCharts/CHANGELOG.md
index 3bc182bd..0e9f02e9 100644
--- a/Assets/XCharts/CHANGELOG.md
+++ b/Assets/XCharts/CHANGELOG.md
@@ -1,6 +1,7 @@
 
 # 更新日志
 
+* (2020.10.22) 完善`HeatmapChart`中`VisualMap`对`Piecewise`的支持
 * (2020.09.22) 修复`PieChart`边框大小不一致的问题
 * (2020.09.19) 发布`v1.6.1`版本
 * (2020.09.19) 增加`Remove All Chart Object`移除图表下的所有子节点（会自动重新初始化）
diff --git a/Assets/XCharts/Runtime/Component/Main/VisualMap.cs b/Assets/XCharts/Runtime/Component/Main/VisualMap.cs
index ebbdaa3a..ab08cafa 100644
--- a/Assets/XCharts/Runtime/Component/Main/VisualMap.cs
+++ b/Assets/XCharts/Runtime/Component/Main/VisualMap.cs
@@ -454,7 +454,7 @@ namespace XCharts
             if (splitNumber <= 0) return -1;
             value = Mathf.Clamp(value, m_Min, m_Max);
 
-            var diff = (m_Max - m_Min) / (splitNumber - (IsPiecewise() ? 0 : 1));
+            var diff = (m_Max - m_Min) / (splitNumber - 1);
             var index = -1;
             for (int i = 0; i < splitNumber; i++)
             {
diff --git a/Assets/XCharts/Runtime/Internal/CoordinateChart_DrawHeatmap.cs b/Assets/XCharts/Runtime/Internal/CoordinateChart_DrawHeatmap.cs
index 2bfe3caa..72b17023 100644
--- a/Assets/XCharts/Runtime/Internal/CoordinateChart_DrawHeatmap.cs
+++ b/Assets/XCharts/Runtime/Internal/CoordinateChart_DrawHeatmap.cs
@@ -282,7 +282,7 @@ namespace XCharts
                     {
                         var splitPos = pos1 + dir * (i - 1 + 0.5f) * splitWid;
                         var startColor = colors[i - 1];
-                        var toColor = colors[i];
+                        var toColor = m_VisualMap.IsPiecewise() ? startColor : colors[i];
                         ChartDrawer.DrawPolygon(vh, splitPos, xRadius, yRadius, startColor, toColor, isVertical);
                     }
                     else if (rangeMin > splitMin && rangeMax >= splitMax)
@@ -291,7 +291,7 @@ namespace XCharts
                         var splitMaxPos = pos1 + dir * i * splitWid;
                         var splitPos = p0 + (splitMaxPos - p0) / 2;
                         var startColor = m_VisualMap.GetColor(m_VisualMap.rangeMin);
-                        var toColor = colors[i];
+                        var toColor = m_VisualMap.IsPiecewise() ? startColor : colors[i];
                         var yRadius1 = Vector3.Distance(p0, splitMaxPos) / 2;
                         if (m_VisualMap.orient == Orient.Vertical)
                             ChartDrawer.DrawPolygon(vh, splitPos, xRadius, yRadius1, startColor, toColor, isVertical);
@@ -304,7 +304,7 @@ namespace XCharts
                         var splitMinPos = pos1 + dir * (i - 1) * splitWid;
                         var splitPos = splitMinPos + (p0 - splitMinPos) / 2;
                         var startColor = colors[i - 1];
-                        var toColor = m_VisualMap.GetColor(m_VisualMap.rangeMax);
+                        var toColor = m_VisualMap.IsPiecewise() ? startColor : m_VisualMap.GetColor(m_VisualMap.rangeMax);
                         var yRadius1 = Vector3.Distance(p0, splitMinPos) / 2;
                         if (m_VisualMap.orient == Orient.Vertical)
                             ChartDrawer.DrawPolygon(vh, splitPos, xRadius, yRadius1, startColor, toColor, isVertical);
@@ -332,7 +332,7 @@ namespace XCharts
                 {
                     var splitPos = pos1 + dir * (i - 1 + 0.5f) * splitWid;
                     var startColor = colors[i - 1];
-                    var toColor = colors[i];
+                    var toColor = m_VisualMap.IsPiecewise() ? startColor : colors[i];
                     ChartDrawer.DrawPolygon(vh, splitPos, xRadius, yRadius, startColor, toColor, isVertical);
                 }
             }