Abstract: 　AIM:To develop an immunoassay for the detection of circulating schistosome antigen (CSA) in host urine.METHODS: CSA extracted from the urine of the rabbits infected with Schistosoma japonicum was used for preparing and selecting specific monoclonal antibody. A one step dot ELISA using this specific McAb and a 2nd antibody was used for detection of circulating schistosome antigen in the urine of infected rabbits. RESULTS: No CSA was detected in urine from all of 22 rabbits before infection. The positive rate of CSA in infected rabbits was correlated with the intensity of infection and the time of infection. No CSA was detected in the urine rabbits of 3 weeks after infection with 25 cercariae while the positive rate of CSA in the urine from rabbits infected with 200 cercariae was 40% and 100% after 3 and 6 weeks, respectively . A combination of CSA detection in both urine and serum may increase the detectability. CONCLUSION:The specific McAb prepared by urine CSA of Schistosoma japonicum infected rabbits can be used as a probe for detecting CSA in the urine of infected rabbits.

Key words: Schistosoma japonicum, urine antigen detection, one step dot ELISA of MaAb 2ndAb