In this paper, a quantization scheme for haptic data compression is proposed and the results of its application to a motion copying system are described. The data compression of image and audio data has been researched a lot. However, the data compression of haptic data has not been much researched yet although the amount of haptic data is large in general. The discrete cosine transform (DCT) is used for the lossy compression of haptic data in this paper. A new quantization scheme using characteristics of DCT is proposed. By using a proposed method, a larger signal-to-noise ratio compared to conventional method is achieved. In the experiment, the validity of the proposed method was verified.