diff --git a/src/core/Board.ts b/src/core/Board.ts
new file mode 100644
index 0000000..c700cb4
--- /dev/null
+++ b/src/core/Board.ts
@@ -0,0 +1,143 @@
+import { Bank, Pit } from './Pit';
+
+const bankCount = 2;
+
+export type PitType =
+  | 'player1Pit'
+  | 'player1Bank'
+  | 'player2Pit'
+  | 'player2Bank';
+
+export class Board {
+  pits: Pit[];
+  playerPitCount: number;
+  initialStoneCountInPits: number;
+
+  onGameMoveStart: (index: number) => void = () => {};
+  onGameMove: (index: number) => void = () => {};
+  onGameMoveEnd: (index: number) => void = () => {};
+
+  constructor(playerPitCount: number, initialStoneCountInPits: number) {
+    this.playerPitCount = playerPitCount;
+    this.initialStoneCountInPits = initialStoneCountInPits;
+    this.pits = this.createPits(playerPitCount, initialStoneCountInPits);
+  }
+
+  createPits(playerPitCount: number, initialStoneCountInPits: number): Pit[] {
+    const totalPitCount = playerPitCount + playerPitCount + bankCount;
+    const pitArray = new Array<Pit>(totalPitCount);
+    for (let index = 0; index < this.totalPitCount(); index++) {
+      const pitType = this.getPitTypeByIndex(index);
+      if (pitType === 'player1Pit' || pitType === 'player2Pit') {
+        pitArray[index] = new Pit(initialStoneCountInPits);
+      } else if (pitType === 'player1Bank' || pitType === 'player2Bank') {
+        pitArray[index] = new Bank(0);
+      }
+    }
+    return pitArray;
+  }
+
+  public player1PitStartIndex = () => 0;
+  public player1PitStopIndex = () =>
+    this.player1PitStartIndex() + this.playerPitCount - 1;
+  public player1BankIndex = () => this.player1PitStopIndex() + 1;
+  public player2PitStartIndex = () => this.player1BankIndex() + 1;
+  public player2PitStopIndex = () =>
+    this.player2PitStartIndex() + this.playerPitCount - 1;
+  public player2BankIndex = () => this.player2PitStopIndex() + 1;
+  public totalPitCount = () => this.player2BankIndex() + 1;
+
+  public checkIndex(index: number): boolean {
+    return (
+      index >= this.player1PitStartIndex() && index <= this.player2BankIndex()
+    );
+  }
+
+  checkIndeAndMaybeThrowError(index: number): void {
+    if (!this.checkIndex(index)) {
+      throw new Error(
+        `IndexOutOfRange => index : ${index} [start, stop] = [${this.player1PitStartIndex()}, ${this.player2BankIndex()}]`
+      );
+    }
+  }
+
+  public getPitTypeByIndex(index: number): PitType {
+    this.checkIndeAndMaybeThrowError(index);
+    if (
+      index >= this.player1PitStartIndex() &&
+      index <= this.player1PitStopIndex()
+    ) {
+      return 'player1Pit';
+    } else if (index === this.player1BankIndex()) {
+      return 'player1Bank';
+    } else if (index <= this.player2PitStopIndex()) {
+      return 'player2Pit';
+    } else {
+      return 'player2Bank';
+    }
+  }
+
+  public move(index: number) {
+    this.checkIndeAndMaybeThrowError(index);
+    const pitType = this.getPitTypeByIndex(index);
+    if (pitType === 'player1Bank' || pitType === 'player2Bank') {
+      throw new Error(`InCorrectPit => index : ${index} pitType = ${pitType}`);
+    }
+    const pit = this.pits[index];
+    if (pit.stoneCount <= 0) {
+      throw new Error(
+        `StoneNotFound => index : ${index} stoneCount = ${pit.stoneCount}`
+      );
+    }
+    const stepCount = pit.stoneCount;
+    this.pits[index].stoneCount = 0;
+    this.fireOnGameMoveStart(index);
+    if (stepCount === 1) {
+      this.fireOnGameMove(index);
+      this.getNextPitCircularly(index).increaseStone();
+      const nextPitIndex = this.getNextPitIndexCircularly(index);
+      this.fireOnGameMove(nextPitIndex);
+      this.fireOnGameMoveEnd(nextPitIndex);
+    } else {
+      for (let i = 0; i < stepCount; i++) {
+        const pit = this.getPitCircularly(index + i);
+        pit.increaseStone();
+        this.fireOnGameMove(index + i);
+      }
+      this.fireOnGameMoveEnd(index + stepCount - 1);
+    }
+  }
+
+  public getNextPitCircularly(currentPitIndex: number) {
+    return this.pits[this.getNextPitIndexCircularly(currentPitIndex)];
+  }
+
+  public getNextPitIndexCircularly(currentPitIndex: number) {
+    this.checkIndeAndMaybeThrowError(currentPitIndex);
+    return this.getPitIndexCircularly(currentPitIndex + 1);
+  }
+
+  public getPitCircularly(currentPitIndex: number) {
+    return this.pits[this.getPitIndexCircularly(currentPitIndex)];
+  }
+
+  public getPitIndexCircularly(currentPitIndex: number) {
+    return currentPitIndex % this.totalPitCount();
+  }
+
+  fireOnGameMoveStart(index: number): void {
+    this.onGameMoveStart(index);
+  }
+
+  fireOnGameMove(index: number): void {
+    this.onGameMove(index);
+  }
+
+  fireOnGameMoveEnd(index: number): void {
+    this.onGameMoveEnd(index);
+  }
+
+  public getStoneArray(): number[] {
+    return [...this.pits.map((pit) => pit.stoneCount)];
+  }
+}
diff --git a/tests/Board.test.ts b/tests/Board.test.ts
new file mode 100644
index 0000000..739ccf7
--- /dev/null
+++ b/tests/Board.test.ts
@@ -0,0 +1,92 @@
+import { Board } from '../src/core/Board';
+
+describe('Board Test', () => {
+  test('test getPitTypeByIndex', () => {
+    const board = new Board(6, 4);
+    expect(board.getPitTypeByIndex(0)).toBe('player1Pit');
+    expect(board.getPitTypeByIndex(1)).toBe('player1Pit');
+    expect(board.getPitTypeByIndex(2)).toBe('player1Pit');
+    expect(board.getPitTypeByIndex(3)).toBe('player1Pit');
+    expect(board.getPitTypeByIndex(4)).toBe('player1Pit');
+    expect(board.getPitTypeByIndex(5)).toBe('player1Pit');
+    expect(board.getPitTypeByIndex(6)).toBe('player1Bank');
+    expect(board.getPitTypeByIndex(7)).toBe('player2Pit');
+    expect(board.getPitTypeByIndex(8)).toBe('player2Pit');
+    expect(board.getPitTypeByIndex(9)).toBe('player2Pit');
+    expect(board.getPitTypeByIndex(10)).toBe('player2Pit');
+    expect(board.getPitTypeByIndex(11)).toBe('player2Pit');
+    expect(board.getPitTypeByIndex(12)).toBe('player2Pit');
+    expect(board.getPitTypeByIndex(13)).toBe('player2Bank');
+    expect(() => board.getPitTypeByIndex(-1)).toThrowError();
+    expect(() => board.getPitTypeByIndex(14)).toThrowError();
+  });
+  test('test checkIndex', () => {
+    const board = new Board(6, 4);
+    expect(board.checkIndex(0)).toBe(true);
+    expect(board.checkIndex(1)).toBe(true);
+    expect(board.checkIndex(2)).toBe(true);
+    expect(board.checkIndex(4)).toBe(true);
+    expect(board.checkIndex(5)).toBe(true);
+    expect(board.checkIndex(6)).toBe(true);
+    expect(board.checkIndex(7)).toBe(true);
+    expect(board.checkIndex(8)).toBe(true);
+    expect(board.checkIndex(9)).toBe(true);
+    expect(board.checkIndex(10)).toBe(true);
+    expect(board.checkIndex(11)).toBe(true);
+    expect(board.checkIndex(12)).toBe(true);
+    expect(board.checkIndex(13)).toBe(true);
+    expect(board.checkIndex(14)).toBe(false);
+    expect(board.checkIndex(-1)).toBe(false);
+  });
+  test('test getPitIndexCircularly', () => {
+    const board = new Board(6, 4);
+    expect(board.getPitIndexCircularly(0)).toBe(0);
+    expect(board.getPitIndexCircularly(1)).toBe(1);
+    expect(board.getPitIndexCircularly(2)).toBe(2);
+    expect(board.getPitIndexCircularly(3)).toBe(3);
+    expect(board.getPitIndexCircularly(4)).toBe(4);
+    expect(board.getPitIndexCircularly(5)).toBe(5);
+    expect(board.getPitIndexCircularly(6)).toBe(6);
+    expect(board.getPitIndexCircularly(7)).toBe(7);
+    expect(board.getPitIndexCircularly(8)).toBe(8);
+    expect(board.getPitIndexCircularly(9)).toBe(9);
+    expect(board.getPitIndexCircularly(10)).toBe(10);
+    expect(board.getPitIndexCircularly(11)).toBe(11);
+    expect(board.getPitIndexCircularly(12)).toBe(12);
+    expect(board.getPitIndexCircularly(13)).toBe(13);
+    expect(board.getPitIndexCircularly(14)).toBe(0);
+    expect(board.getPitIndexCircularly(15)).toBe(1);
+    expect(board.getPitIndexCircularly(16)).toBe(2);
+  });
+  test('test move', () => {
+    const board = new Board(6, 4);
+    const initialBoard = [4, 4, 4, 4, 4, 4, 0, 4, 4, 4, 4, 4, 4, 0];
+    expect(board.getStoneArray()).toStrictEqual(initialBoard);
+    board.move(0);
+    expect(board.getStoneArray()).toStrictEqual([
+      1, 5, 5, 5, 4, 4, 0, 4, 4, 4, 4, 4, 4, 0
+    ]);
+    board.move(0);
+    expect(board.getStoneArray()).toStrictEqual([
+      0, 6, 5, 5, 4, 4, 0, 4, 4, 4, 4, 4, 4, 0
+    ]);
+    board.move(1);
+    expect(board.getStoneArray()).toStrictEqual([
+      0, 1, 6, 6, 5, 5, 1, 4, 4, 4, 4, 4, 4, 0
+    ]);
+    board.move(5);
+    expect(board.getStoneArray()).toStrictEqual([
+      0, 1, 6, 6, 5, 1, 2, 5, 5, 5, 4, 4, 4, 0
+    ]);
+  });
+  test('test move 2', () => {
+    const board = new Board(6, 4);
+    board.pits[5].stoneCount = 15;
+    const initialBoard = [4, 4, 4, 4, 4, 15, 0, 4, 4, 4, 4, 4, 4, 0];
+    expect(board.getStoneArray()).toStrictEqual(initialBoard);
+    board.move(5);
+    expect(board.getStoneArray()).toStrictEqual([
+      5, 5, 5, 5, 5, 2, 1, 5, 5, 5, 5, 5, 5, 1
+    ]);
+  });
+});