There is higher and higher demand for realistic computer-generated animation of natural phenomena based on the physical computation. Simulation for depicting realistic liquid motion requires high computational cost, and no versatile method is available. Water drops, which are in various scenes, cannot be depicted realistically by simulation in real time because of their specific physical features and the high computational cost. This paper proposes using extended smoothed particle hydrodynamics which simulates liquid motion with particles, to depict water drops with an interfacial tension model. The proposed method enables simulation of flat-shaped water drops with different contact angles.