diff --git a/Intar.Tests/AnimationCurveTest.Unity.cs b/Intar.Tests/AnimationCurveTest.Unity.cs
index 691c5341a..864424ce3 100644
--- a/Intar.Tests/AnimationCurveTest.Unity.cs
+++ b/Intar.Tests/AnimationCurveTest.Unity.cs
@@ -48,5 +48,31 @@ public static void TestAnimationCurveConstructor() {
             Assert.IsNotNull(curve.keys);
             Assert.AreEqual(0, curve.length);
         }
+
+        [Test]
+        public static void TestSetKeys() {
+            var keys = new Keyframe[] {
+                new Keyframe(4, 5),
+                new Keyframe(4, 4),
+                new Keyframe(3, 4),
+                new Keyframe(3, 3),
+                new Keyframe(2, 3),
+                new Keyframe(2, 2),
+                new Keyframe(1, 2),
+                new Keyframe(1, 1),
+            };
+            var curve = new AnimationCurve { keys = keys };
+
+            // keys 設定時, 値が安定ソートされることをテスト
+            Assert.AreEqual(8, curve.length);
+            Assert.AreEqual(keys[6], curve[0]);
+            Assert.AreEqual(keys[7], curve[1]);
+            Assert.AreEqual(keys[4], curve[2]);
+            Assert.AreEqual(keys[5], curve[3]);
+            Assert.AreEqual(keys[2], curve[4]);
+            Assert.AreEqual(keys[3], curve[5]);
+            Assert.AreEqual(keys[0], curve[6]);
+            Assert.AreEqual(keys[1], curve[7]);
+        }
     }
 }
diff --git a/Intar.Tests/AnimationCurveTest.cs b/Intar.Tests/AnimationCurveTest.cs
index 6cab910e8..a99516525 100644
--- a/Intar.Tests/AnimationCurveTest.cs
+++ b/Intar.Tests/AnimationCurveTest.cs
@@ -39,5 +39,32 @@ public static void TestAnimationCurveI17F15Constructor() {
             Assert.IsNotNull(curve.Keys);
             Assert.AreEqual(0, curve.Length);
         }
+
+        [Test]
+        public static void TestSetKeysI17F15() {
+            var keys = new KeyframeI17F15[] {
+                new KeyframeI17F15(I17F15.FromBits(4000), I17F15.FromBits(5000)),
+                new KeyframeI17F15(I17F15.FromBits(4000), I17F15.FromBits(4000)),
+                new KeyframeI17F15(I17F15.FromBits(3000), I17F15.FromBits(4000)),
+                new KeyframeI17F15(I17F15.FromBits(3000), I17F15.FromBits(3000)),
+                new KeyframeI17F15(I17F15.FromBits(2000), I17F15.FromBits(3000)),
+                new KeyframeI17F15(I17F15.FromBits(2000), I17F15.FromBits(2000)),
+                new KeyframeI17F15(I17F15.FromBits(1000), I17F15.FromBits(2000)),
+                new KeyframeI17F15(I17F15.FromBits(1000), I17F15.FromBits(1000)),
+            };
+            var curve = new AnimationCurveI17F15 { Keys = keys };
+
+            // Keys 設定時, 値が安定ソートされることをテスト
+            Assert.AreEqual(8, curve.Length);
+            Assert.AreEqual(keys[6], curve[0]);
+            Assert.AreEqual(keys[7], curve[1]);
+            Assert.AreEqual(keys[4], curve[2]);
+            Assert.AreEqual(keys[5], curve[3]);
+            Assert.AreEqual(keys[2], curve[4]);
+            Assert.AreEqual(keys[3], curve[5]);
+            Assert.AreEqual(keys[0], curve[6]);
+            Assert.AreEqual(keys[1], curve[7]);
+        }
+
     }
 }
diff --git a/Intar/AnimationCurveI17F15.cs b/Intar/AnimationCurveI17F15.cs
index daf5384e8..e1a1a64a2 100644
--- a/Intar/AnimationCurveI17F15.cs
+++ b/Intar/AnimationCurveI17F15.cs
@@ -85,6 +85,7 @@ public KeyframeI17F15[] Keys {
                     return;
                 }
                 keys = new List<KeyframeI17F15>(value);
+                Utility.InsertionSort(keys, (a, b) => a.Time.CompareTo(b.Time));
             }
         }
         public int Length {
diff --git a/Intar/Utility.cs b/Intar/Utility.cs
new file mode 100644
index 000000000..889151940
--- /dev/null
+++ b/Intar/Utility.cs
@@ -0,0 +1,22 @@
+using System;
+using System.Collections.Generic;
+
+namespace Intar {
+    /// <summary>
+    /// 主に実装用のユーティリティクラス
+    /// </summary>
+    static class Utility {
+        internal static void InsertionSort<T>(IList<T> list, Comparison<T> comparison) {
+            var count = list.Count;
+            for (var i = 1; i < count; i++) {
+                var key = list[i];
+                var j = i - 1;
+                while (0 <= j && 0 < comparison(list[j], key)) {
+                    list[j + 1] = list[j];
+                    j--;
+                }
+                list[j + 1] = key;
+            }
+        }
+    }
+}
diff --git a/Intar/Utility.cs.meta b/Intar/Utility.cs.meta
new file mode 100644
index 000000000..bb110110c
--- /dev/null
+++ b/Intar/Utility.cs.meta
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: fe2eea8ac0eb02740bb044dcd32f2edf
\ No newline at end of file