The circulating antigens of Schistosoma japonicum and the antibodies against the worm in the sera of patients were detected concurrently by Dot-ELISA.In 30 sera from patients with acute schistosomiasis, 51 sera from patients with chronic schistosomiasis and 30 sera from patients being treated by praziquantel 5=6 years ago, the positive rates of the circulating antigens were 86.7%, 78.4% and 23.3% respectively, but all negative in 30 sera from patients with clonorchiasis sinensis. One of the 40 sera from healthy individuals had a weak positive reaction. The positive rates of the antibodies in those acute, chronic and treated patients with schistosomiasis were 100.0%,96.1% and 30.0%; the mean titers of antibodies were 1 : 367.6, 1 : 181.7 and 1 : 9.8 respectively; Two sera from patients with clonorchiasis were positive. All of the healthy individuals were negative.The results indicaded that the circulating antigen was in accord with the antibodies in most sera from schistosomiasis patients.