This study describes a group robot system “CHOBIE II”. The feature of the CHOBIE II is a function to form a reconfigurable structure. In the previous paper, we introduced a control method of the robots and realized transformation of the structure. In this paper, we focus on a motion planning method to obtain control algorithms. For this purpose, we introduce a numerical criterion for generating transformations. The criterion is expressed with matrix form of 32 parameters. This paper demonstrates the criteria generate various motions of the CHOBIE II, and proposes a new method to obtain the appropriate parameters for objective motions.