Abstract: Objective To understand cognition and knowledge acquirement of unlicensed medical practice among the floating population in Shanghai city and to provide scientific basis for effective intervention.Methods With stratified sampling,we conducted a questionnaire survey among 1 883 floating people selected from towns(communities) in Qingpu district of Shanghai.Results Among the participants,477(25.3%) did not aware that health care setting should obtain permission from the health administration of local government.Inexpensive medical cost,time-saving and convenient locatio near living place were the main reasons for the participants to attend unlicensed medical setting.The ways to acquire information on the hazard to get medical service in unlicensed medical setting were from television(1 147,60.9%),communication with crowd(730,38.8%),and from newspapers and brochures.Conclusion The cognition of unlicensed medical practice among the floating population in Qingpu district of Shanghai is at lowlevel.The most effective way to acquire information on the hazard to get medical service in unlicensed medical setting is from television,followed by cmonunication with the crowd,and from newspapers and brochures.