As both the Sandae(山臺) of Korea and the Aoshan(鰲山) of China have been derived from Buddhism, the meaning of the mountains was limited, at first, to the Buddha-mountain, where the gods of Buddhism reside. However, in the later process of historical development, the objects of each folk religion have naturally penetrated, and consequently, Aoshan or Sandae got the meaning of Sinsan(神山), a dwelling of various gods. In terms of origin, both Sandae of Korea and Aoshan of China have been identified to have their roots in the movement of the statue of Bhddhism. So its original form was movable type, and the unmovable type was considered to have appeared later than the movable type. When we look into Japan based on these results, the following two facts attract our attention: First, numerous Sancha(山車)s, which are still performed throughout Japan today, although their origin still needs to be discussed meticulously in the future, are practically not different from those in Korea and China in that they are trying to build various Sinsans. Second, the history of performing arts of ancient Japan developed in close relationship with China and Korea as well as the inflow of Ho waves(胡流) were also obvious in such mutual relationship. Thus, there is a high possibility for the Japanese Sancha to have had a close relationship with Sandae or Aoshan. This paper is one of the attempts to trace the triangular relationship in the history of performing arts of Korea, China and Japan. For the consistency of argurment and efficiency of discussion, the scope of the consideration of this study was limited to the structural characteristics, similarities and differences of Sinsans that had been performed or still performed in Korea, China and Japan. Based on nine important criteria considered essential in analyzing the triangular relationship among Korea, China and Japan, the structural characteristics of their Sinsans as well as their similarities and differences be summarized as below: The Sinsans in the history of performing arts of Korea, China and Japan have substantial identity with negligible differences. In conclusion, the structural characteristics of the Sinsans in Korea, China and Japan as well as their similarities and differences identified so far occurred in the process of the independent acceptance and development by the people of those three countries in response to the westward migration of Ho waves that started from the Western Area. This paper will not only widen the horizon of Korean mask dance-drama but also significantly contribute to the efforts of the people to more deeply understand the history of performing arts of Korea, China and Japan from an integrated point of view.