diff --git a/Services/ExcelExportService.cs b/Services/ExcelExportService.cs
index 62c412c..c5e474b 100644
--- a/Services/ExcelExportService.cs
+++ b/Services/ExcelExportService.cs
@@ -259,9 +259,12 @@ namespace TabletTester2025.Services
                 header.Style.Font.Bold = true;
             }
 
+            int dataEndRow = seriesGroups.Max(group => group.Points.Count) + 1;
+            int chartStartRow = dataEndRow + 2;
+
             var chart = sheet.Drawings.AddChart("DissolutionCurve", eChartType.LineMarkers);
             chart.Title.Text = "溶出曲线";
-            chart.SetPosition(1, 0, column, 0);
+            chart.SetPosition(chartStartRow - 1, 0, 0, 0);
             chart.SetSize(900, 420);
             chart.XAxis.Title.Text = "计划时间(min)";
             chart.YAxis.Title.Text = "溶出度(%)";