Recently the demand of 3D models has been growing in the CG production and the video game industry. Many 3D models have already been created and stored. We need a 3D model database system that allows us to retrieve required 3D models quickly and accurately. In the design of 3D model database systems, there is the question which feature of 3D models is suitable as the similarity measure for 3D model searches. In this paper, the authors propose the use of OBBTree for the similarity measure and describe its usefulness by showing its experimental results and comparison results with the recent major method called D2. The proposed method showed better results than D2.