Objective: To identify the construction and characteristics of methadone maintenance treatment(MMT) patients who were double threatened by AIDS and social discrimination,and discuss the relationship between retention and their social network. Methods: Using SPSS and qualitative study to analyze, 277 subjects were recruited by convenience sampling and combined structured interview to conduct a social epidemiological survey. Results: The population were largely prejudiced, their social contact and social network limited to non-normal social groups such as family members and several friends owing to less interaction with society and being labeled with drug abuser. Normal social support network had not play a key role in their treatments,retention and social assistance. Conclusion: The characteristics of MMT patients would influence the effect of treatment. The authors advanced that reinforce interaction between this population with normal social network would be significant for their family and social function improvement.