diff --git a/native/jni/Android.mk b/native/jni/Android.mk
index c1372bd..5c117ce 100644
--- a/native/jni/Android.mk
+++ b/native/jni/Android.mk
@@ -87,6 +87,8 @@
 LOCAL_LDFLAGS += -ldl
 
 include $(BUILD_SHARED_LIBRARY)
-
 #################### Clean up the tmp vars
 include $(LOCAL_PATH)/CleanupNativeFileList.mk
+
+#################### Unit test on host environment
+include $(LOCAL_PATH)/HostUnitTests.mk
diff --git a/native/jni/CleanupNativeFileList.mk b/native/jni/CleanupNativeFileList.mk
index 5420f16..1738f8c 100644
--- a/native/jni/CleanupNativeFileList.mk
+++ b/native/jni/CleanupNativeFileList.mk
@@ -13,5 +13,6 @@
 # limitations under the License.
 
 LATIN_IME_CORE_SRC_FILES :=
+LATIN_IME_CORE_TEST_FILES :=
 LATIN_IME_JNI_SRC_FILES :=
 LATIN_IME_SRC_DIR :=
diff --git a/native/jni/HostUnitTests.mk b/native/jni/HostUnitTests.mk
new file mode 100644
index 0000000..828edce
--- /dev/null
+++ b/native/jni/HostUnitTests.mk
@@ -0,0 +1,53 @@
+# Copyright (C) 2014 The Android Open Source Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+LOCAL_PATH := $(call my-dir)
+
+######################################
+include $(CLEAR_VARS)
+
+include $(LOCAL_PATH)/NativeFileList.mk
+
+#################### Host library for unit test
+# TODO: Remove -std=c++11 once it is set by default on host build.
+LATIN_IME_SRC_DIR := src
+LOCAL_CFLAGS += -std=c++11 -Wno-unused-parameter -Wno-unused-function
+LOCAL_CLANG := true
+LOCAL_C_INCLUDES += $(LOCAL_PATH)/$(LATIN_IME_SRC_DIR)
+LOCAL_IS_HOST_MODULE := true
+LOCAL_MODULE := liblatinime_host_static_for_unittests
+LOCAL_MODULE_TAGS := optional
+LOCAL_NDK_STL_VARIANT := c++_static
+LOCAL_SRC_FILES := $(addprefix $(LATIN_IME_SRC_DIR)/, $(LATIN_IME_CORE_SRC_FILES))
+include $(BUILD_HOST_STATIC_LIBRARY)
+
+#################### Host native tests
+include $(CLEAR_VARS)
+LATIN_IME_TEST_SRC_DIR := tests
+# TODO: Remove -std=c++11 once it is set by default on host build.
+LOCAL_CFLAGS += -std=c++11 -Wno-unused-parameter -Wno-unused-function
+LOCAL_CLANG := true
+LOCAL_C_INCLUDES += $(LOCAL_PATH)/$(LATIN_IME_SRC_DIR)
+LOCAL_IS_HOST_MODULE := true
+LOCAL_MODULE := liblatinime_host_unittests
+LOCAL_MODULE_TAGS := tests
+LOCAL_NDK_STL_VARIANT := c++_static
+LOCAL_SRC_FILES := $(addprefix $(LATIN_IME_TEST_SRC_DIR)/, $(LATIN_IME_CORE_TEST_FILES))
+LOCAL_STATIC_LIBRARIES += liblatinime_host_static_for_unittests libgtest_host libgtest_main_host
+include $(BUILD_HOST_NATIVE_TEST)
+
+#################### Clean up the tmp vars
+LATIN_IME_SRC_DIR :=
+LATIN_IME_TEST_SRC_DIR :=
+include $(LOCAL_PATH)/CleanupNativeFileList.mk
diff --git a/native/jni/NativeFileList.mk b/native/jni/NativeFileList.mk
index 2ee4caa..3da9d56 100644
--- a/native/jni/NativeFileList.mk
+++ b/native/jni/NativeFileList.mk
@@ -99,3 +99,6 @@
         char_utils.cpp \
         log_utils.cpp \
         time_keeper.cpp)
+
+LATIN_IME_CORE_TEST_FILES := \
+    utils/autocorrection_threshold_utils_test.cpp
diff --git a/native/jni/tests/utils/autocorrection_threshold_utils_test.cpp b/native/jni/tests/utils/autocorrection_threshold_utils_test.cpp
new file mode 100644
index 0000000..cc8db70
--- /dev/null
+++ b/native/jni/tests/utils/autocorrection_threshold_utils_test.cpp
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "utils/autocorrection_threshold_utils.h"
+
+#include <gtest/gtest.h>
+
+#include <vector>
+
+namespace latinime {
+namespace {
+
+int CalcEditDistance(const std::vector<int> &before,
+        const std::vector<int> &after) {
+    return AutocorrectionThresholdUtils::editDistance(
+            &before[0], before.size(), &after[0], after.size());
+}
+
+TEST(AutocorrectionThresholdUtilsTest, SameData) {
+    EXPECT_EQ(0, CalcEditDistance({1}, {1}));
+    EXPECT_EQ(0, CalcEditDistance({2, 2}, {2, 2}));
+    EXPECT_EQ(0, CalcEditDistance({3, 3, 3}, {3, 3, 3}));
+}
+
+}  // namespace
+}  // namespace latinime