This paper proposes an identification method of unknown environment for motion control. The proposed method can estimate a physical model and its parameter simultaneously by using element description method. In this paper, the proposed method is applied to identification of environmental characteristics. General identification methods need to decide a physical model of target in advance. In another approaches such as neural network and black-box modeling methods by database, notwithstanding achieving input-output characteristics, these methods are difficult to understand the physical meaning of target environment. On the contrary, the proposed method can identify not only parameter but also a physical model of environment, which is the merit of the proposed method. Also the physical meaning of target environment is understandable according to element description. By using the proposed method, ideal controller for contact task can be designed based on environmental model and its parameter. It may be possible to discover a new physical property of environment.