Abstract: Objective To understand changes of the knowledge,attitude and practice abouthIV/AIDS among medical clients in STD clinics in the past five years so as to offer basis for making a tactics and measure on HIV/AIDS.Methods A self-adminnisterd questionnaire was used to collect the infor mation including knowledge,attitude and practice abouthIV/AIDS among the top 50 clients in 17 STD clinics supported by the Health鵳roject from August to October in 2001 and 2006.Results The knowing rate of route of transmission of AIDS rosed from 70.6% of 2001 to 73.6% of 2006;The rate of utilization of condom rosed form 60.5% of 2001 to 61.2% of 2006;Rate of correct attitude towards HIV/AIDS rosed from 11.2% of 2001 to 31.6% of 2006.Conclusion Knowing rate of knowledge about HIV/AIDs is high,but the rate of utilization of condom is low.The discrimination to patients with HIV/AIDS is still serious.The propaganda work should be changed from relevant knowledge to behavior intervention.