diff --git a/CHANGELOG.md b/CHANGELOG.md
index 507b7f4bd..2f682f114 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,7 @@
 - [#268](https://github.com/arkedge/c2a-core/pull/268): GS と FSW 側での同期のために，BCT, TL のダイジェスト (CRC) を下ろせるようにする App の追加
 - [#237](https://github.com/arkedge/c2a-core/pull/237): 任意の Component Driver に対して，任意バイト列の送受信と HAL init, reopen Cmd を提供する
 - [#274](https://github.com/arkedge/c2a-core/pull/274): `TMGR_get_master_mode_cycle_in_msec` などの in_sec 版を実装
+- [#260](https://github.com/arkedge/c2a-core/pull/260): C2A 初期化時に実行環境のエンディアンが設定と正しいかチェックする
 
 ### Breaking Changes
 
diff --git a/c2a_core_main.c b/c2a_core_main.c
index 157acfebb..f1ec5a8fb 100644
--- a/c2a_core_main.c
+++ b/c2a_core_main.c
@@ -3,6 +3,7 @@
 
 #include "./library/git_revision.h"
 #include "./library/print.h"
+#include "./library/endian.h"
 #include "./system/task_manager/task_dispatcher.h"
 #include "./system/application_manager/app_manager.h"
 #include "./system/event_manager/event_manager.h"
@@ -15,6 +16,7 @@
 #include "./tlm_cmd/telemetry_frame.h"
 
 #include <src_user/applications/app_registry.h>
+#include <src_user/settings/build_settings.h>
 
 // git revisionをコードに埋め込む
 const char GIT_REV_CORE[41]         = GIT_REVISION_C2A_CORE;
@@ -24,6 +26,21 @@ const uint32_t GIT_REV_USER_SHORT   = GIT_REVISION_C2A_USER_SHORT;
 
 void C2A_core_init(void)
 {
+  // エンディアンの設定が正しいかの確認
+#ifdef IS_LITTLE_ENDIAN
+  if (ENDIAN_detect_system_endian() != ENDIAN_TYPE_LITTLE)
+#else
+  if (ENDIAN_detect_system_endian() != ENDIAN_TYPE_BIG)
+#endif
+  {
+    Printf("WARNING: ENDIAN MISMATCH BETWEEN BUILD SETTINGS AND RUNTIME!\n");
+  }
+  else
+  {
+    Printf("C2A_init: Endian OK.\n");
+  }
+
+  // C2A の初期化
   CA_initialize();            // Cmd Analyze
   Printf("C2A_init: CA_initialize done.\n");
   TF_initialize();            // TLM frame
diff --git a/library/endian.c b/library/endian.c
index 77f144c81..7621839ff 100644
--- a/library/endian.c
+++ b/library/endian.c
@@ -37,4 +37,23 @@ void ENDIAN_conv(void* after, const void* before, size_t size)
   return;
 }
 
+ENDIAN_TYPE ENDIAN_detect_system_endian(void)
+{
+  uint32_t test = 0x12345678;
+  uint8_t* p = (uint8_t*)&test;
+
+  if (*p == 0x12)
+  {
+    return ENDIAN_TYPE_BIG;
+  }
+  else if (*p == 0x78)
+  {
+    return ENDIAN_TYPE_LITTLE;
+  }
+  else
+  {
+    return ENDIAN_TYPE_UNKNOWN;
+  }
+}
+
 #pragma section
diff --git a/library/endian.h b/library/endian.h
index 814cf9b14..53a199874 100644
--- a/library/endian.h
+++ b/library/endian.h
@@ -40,4 +40,11 @@ void* ENDIAN_memcpy(void* dest, const void* src, size_t size);
  */
 void ENDIAN_conv(void* after, const void* before, size_t size);
 
+/**
+ * @brief  実行環境のエンディアンを判定する
+ * @param  void
+ * @return ENDIAN_TYPE
+ */
+ENDIAN_TYPE ENDIAN_detect_system_endian(void);
+
 #endif