diff --git a/__test__/Polyline/PointInPolyline.test.ts b/__test__/Polyline/PointInPolyline.test.ts
index 157892baa..5d6abb912 100644
--- a/__test__/Polyline/PointInPolyline.test.ts
+++ b/__test__/Polyline/PointInPolyline.test.ts
@@ -179,7 +179,7 @@ describe("", () =>
         expect(pl.PtInCurve(p)).toBeFalsy();
     });
 
-    test('同样是因为精度导致的错误IKOTO', () =>
+    test('圆弧起点切线与直线相切IKOTO', () =>
     {
         let f = new CADFile();
         f.Data =
@@ -192,4 +192,18 @@ describe("", () =>
         expect(pl.PtInCurve(p)).toBeFalsy();
     });
 
+
+    test('大圆弧', () =>
+    {
+
+        let f = new CADFile();
+        f.Data =
+            [1, ["Polyline", 1, 1, 5, false, 7, -1, [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1], 2, 3, [5.113122171945702, 3.235294117647059], 2.037852023242286, [6.69683257918552, 0.7918552036199095], 0, [5.113122171945702, 3.235294117647059], 0, false]]
+        let p = new Vector3().fromArray([5.113122171945701, 0.7239819004524888, 0]);
+
+        f.Read();
+        let pl = f.ReadObject() as Polyline;
+        expect(pl.PtInCurve(p)).toBeTruthy();
+    });
+
 })
diff --git a/src/DatabaseServices/PointInPolyline.ts b/src/DatabaseServices/PointInPolyline.ts
index 06f7ab7cf..b13a62e62 100644
--- a/src/DatabaseServices/PointInPolyline.ts
+++ b/src/DatabaseServices/PointInPolyline.ts
@@ -84,12 +84,16 @@ export function IsPointInPolyLine(pl: Polyline, pt: Vector3): boolean
             if (equal(pti, cu.StartPoint))
             {
                 let der = cu.GetFistDeriv(0);
+                if (equaln(der.x, 0) && cu instanceof Arc)
+                    der = cu.GetFistDeriv(0.1);
                 if (der.x < -1e-4) //左边+ 右边0
                     crossings++;
             }
             else if (equal(pti, cu.EndPoint))
             {
                 let der = cu.GetFistDeriv(1);
+                if (equaln(der.x, 0) && cu instanceof Arc)
+                    der = cu.GetFistDeriv(0.9);
                 if (der.x > 1e-4) //左边+ 右边0
                     crossings++;
             }