diff --git a/doublearray/doublearray-tests.ts b/doublearray/doublearray-tests.ts
new file mode 100644
index 0000000000..e54a58fd0f
--- /dev/null
+++ b/doublearray/doublearray-tests.ts
@@ -0,0 +1,32 @@
+/// <reference path="doublearray.d.ts" />
+
+// https://github.com/takuyaa/doublearray/blob/master/README.md
+var words = [
+    { k: 'a', v: 1 },
+    { k: 'abc', v: 2 },
+    { k: '奈良', v: 3 },
+    { k: '奈良先端', v: 4 },
+    { k: '奈良先端科学技術大学院大学', v: 5 }
+];
+
+var trie = doublearray.builder().build(words);
+
+var trie = doublearray
+    .builder()
+    .append('a', 1)
+    .append('abc', 2)
+    .append('奈良', 3)
+    .append('奈良先端', 4)
+    .append('奈良先端科学技術大学院大学', 5)
+    .build();
+
+trie.contain('a');
+
+trie.lookup('abc');
+
+trie.commonPrefixSearch('奈良先端科学技術大学院大学');
+
+var base_buffer: Int32Array = trie.bc.getBaseBuffer();
+var check_buffer: Int32Array = trie.bc.getCheckBuffer();
+
+var loaded_trie = doublearray.load(base_buffer, check_buffer);
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diff --git a/doublearray/doublearray.d.ts b/doublearray/doublearray.d.ts
new file mode 100644
index 0000000000..b34aa4cb83
--- /dev/null
+++ b/doublearray/doublearray.d.ts
@@ -0,0 +1,99 @@
+// Type definitions for doublearray
+// Project: https://github.com/takuyaa/doublearray
+// Definitions by: MIZUSHIMA Junki <https://github.com/mzsm>
+// Definitions: https://github.com/borisyankov/DefinitelyTyped
+
+declare module doublearray {
+    interface KeyValue {
+        k: string;
+        v: number;
+    }
+
+    interface BaseAndCheck {
+        getBaseBuffer(): any;   // Int8Array | Int16Array | Int32Array | Uint8Array | Uint16Array | Uint32Array
+        getCheckBuffer(): any;  // Int8Array | Int16Array | Int32Array | Uint8Array | Uint16Array | Uint32Array
+        loadBaseBuffer(base_buffer: Int8Array): BaseAndCheck;
+        loadBaseBuffer(base_buffer: Int16Array): BaseAndCheck;
+        loadBaseBuffer(base_buffer: Int32Array): BaseAndCheck;
+        loadBaseBuffer(base_buffer: Uint8Array): BaseAndCheck;
+        loadBaseBuffer(base_buffer: Uint16Array): BaseAndCheck;
+        loadBaseBuffer(base_buffer: Uint32Array): BaseAndCheck;
+        loadCheckBuffer(check_buffer: Int8Array): BaseAndCheck;
+        loadCheckBuffer(check_buffer: Int16Array): BaseAndCheck;
+        loadCheckBuffer(check_buffer: Int32Array): BaseAndCheck;
+        loadCheckBuffer(check_buffer: Uint8Array): BaseAndCheck;
+        loadCheckBuffer(check_buffer: Uint16Array): BaseAndCheck;
+        loadCheckBuffer(check_buffer: Uint32Array): BaseAndCheck;
+        size(): number;
+        getBase(): number;
+        getCheck(): number;
+        setBase(index: number, base_value: number): void;
+        setCheck(index: number, check_value: number): void;
+        setFirstUnusedNode(index: number): void;
+        getFirstUnusedNode(): number;
+        shrink(): void;
+        calc(): {all: number; unused: number;  efficiency: number};
+        dump(): string;
+    }
+
+    interface DoubleArrayBuilder {
+        bc: BaseAndCheck;
+        keys: KeyValue[];
+        append(key: string, record: number): DoubleArrayBuilder;
+        build(keys?: KeyValue[], sorted?: boolean): DoubleArray;
+        getChildrenInfo(position: number, start: number, length: number): Int32Array;
+        setBC(parent_id: number, children_info: Int32Array, _base: number): void;
+        findAllocatableBase(children_info: Int32Array): number;
+        isUnusedNode(index: number): boolean;
+    }
+
+    interface DoubleArray {
+        bc: BaseAndCheck;
+        contain(key: string): boolean;
+        lookup(key: string): number;
+        commonPrefixSearch(key: string): KeyValue;
+        traverse(parent: number, code: number): number;
+        size(): number;
+        calc(): {all: number; unused: number;  efficiency: number};
+        dump(): string;
+    }
+
+    export function builder(initial_size?: number): DoubleArrayBuilder;
+    // TODO: Replace to union types in the future.
+    export function load(base_buffer: Int8Array, check_buffer: Int8Array): DoubleArray;
+    export function load(base_buffer: Int8Array, check_buffer: Int16Array): DoubleArray;
+    export function load(base_buffer: Int8Array, check_buffer: Int32Array): DoubleArray;
+    export function load(base_buffer: Int8Array, check_buffer: Uint8Array): DoubleArray;
+    export function load(base_buffer: Int8Array, check_buffer: Uint16Array): DoubleArray;
+    export function load(base_buffer: Int8Array, check_buffer: Uint32Array): DoubleArray;
+    export function load(base_buffer: Int16Array, check_buffer: Int8Array): DoubleArray;
+    export function load(base_buffer: Int16Array, check_buffer: Int16Array): DoubleArray;
+    export function load(base_buffer: Int16Array, check_buffer: Int32Array): DoubleArray;
+    export function load(base_buffer: Int16Array, check_buffer: Uint8Array): DoubleArray;
+    export function load(base_buffer: Int16Array, check_buffer: Uint16Array): DoubleArray;
+    export function load(base_buffer: Int16Array, check_buffer: Uint32Array): DoubleArray;
+    export function load(base_buffer: Int32Array, check_buffer: Int8Array): DoubleArray;
+    export function load(base_buffer: Int32Array, check_buffer: Int16Array): DoubleArray;
+    export function load(base_buffer: Int32Array, check_buffer: Int32Array): DoubleArray;
+    export function load(base_buffer: Int32Array, check_buffer: Uint8Array): DoubleArray;
+    export function load(base_buffer: Int32Array, check_buffer: Uint16Array): DoubleArray;
+    export function load(base_buffer: Int32Array, check_buffer: Uint32Array): DoubleArray;
+    export function load(base_buffer: Uint8Array, check_buffer: Int8Array): DoubleArray;
+    export function load(base_buffer: Uint8Array, check_buffer: Int16Array): DoubleArray;
+    export function load(base_buffer: Uint8Array, check_buffer: Int32Array): DoubleArray;
+    export function load(base_buffer: Uint8Array, check_buffer: Uint8Array): DoubleArray;
+    export function load(base_buffer: Uint8Array, check_buffer: Uint16Array): DoubleArray;
+    export function load(base_buffer: Uint8Array, check_buffer: Uint32Array): DoubleArray;
+    export function load(base_buffer: Uint16Array, check_buffer: Int8Array): DoubleArray;
+    export function load(base_buffer: Uint16Array, check_buffer: Int16Array): DoubleArray;
+    export function load(base_buffer: Uint16Array, check_buffer: Int32Array): DoubleArray;
+    export function load(base_buffer: Uint16Array, check_buffer: Uint8Array): DoubleArray;
+    export function load(base_buffer: Uint16Array, check_buffer: Uint16Array): DoubleArray;
+    export function load(base_buffer: Uint16Array, check_buffer: Uint32Array): DoubleArray;
+    export function load(base_buffer: Uint32Array, check_buffer: Int8Array): DoubleArray;
+    export function load(base_buffer: Uint32Array, check_buffer: Int16Array): DoubleArray;
+    export function load(base_buffer: Uint32Array, check_buffer: Int32Array): DoubleArray;
+    export function load(base_buffer: Uint32Array, check_buffer: Uint8Array): DoubleArray;
+    export function load(base_buffer: Uint32Array, check_buffer: Uint16Array): DoubleArray;
+    export function load(base_buffer: Uint32Array, check_buffer: Uint32Array): DoubleArray;
+}
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