In the ray-tracing method, radio propagation is approximately represented by using reflected and diffracted rays. Thus an arrival angle of incoming wave can be known easily by using the path of ray. On the other hand, in the FDTD method, a propagation wave is calculated strictly based on Maxwell's equations. Therefore, it seems difficult to know the arrival angle of incoming wave in the FDTD analysis. However, it is expected that the arrival angle of incoming wave can be obtained by using the direction of arrival estimation method in the FDTD analysis. In this paper, the direction of arrival estimation in the FDTD analysis of radio propagation using the MUSIC method is investigated.