The present study is aimed at exploring the characteristics of Chinese relapsed drug users associated with their treatment experience in police mandatory treatment centers. The exploration is based on a comparison of Chinese drug users who received the police mandatory treatment for multiple times (the "relapse" group) with those who had the treatment for the first time (the "first-time" group). The comparative analysis is conducted using data collected from a 2009 survey of 177 drug users in several police mandatory treatment centers in a large city of China. The data indicate that both the "relapse" and the "first-time" groups have similar demographic characteristics except age. However, respondents in the "relapse" group were more likely to be heroin users, have a high level of drug dependence, have prior treatment, experience a high level of mental disorder, and have drug-use friends than those in the "first-time" group. The findings imply that relapse among Chinese drug users are likely to have multiple factors which is comparable to that discovered in Western research.