Money boys have become one of the emerging populations in the underground sex industry in China in recent years.Due to the rapid spread of HIV infection among Chinese MBs,MB is now one of the targeted populations in the HIV/AIDS intervention and prevention programs.This qualitative study employed participant observation,in-depth interview and focus-group methods to investigate the sexual networks among MBs and the operation mechanism of the sex industry in Northeast China.HIV intervention programs targeted different venues,services and self-identity among MBs should be implemented.