The rapid development of large Chinese orchestras leads to a problem about the timbre perception of Chinese traditional music that the instrumental ensemble does not reach the musical consonance defined by western musical theory. To better understand the special timbre structure of Chinese traditional instruments, this paper investigated the perceptual attributes of 18 instrumental samples. Listening tests were conducted to assess the timbre similarity. A number of acoustic features were analyzed with subjective evaluation results using Multi-Dimensional Scaling (MDS) technique. Results indicated that low energy distribution and brightness were principal acoustic factors for timbre perception, which was different from conclusions of western musical instruments.