Abstract: Monoclonal antibodies (McAbs) were generated from mice immunized with soluble egg antigen (SEA) of Schistosoma japonicum.Five of which were specific to SEA of S.ja-ponicum.The isotype of these McAbs was IgG1.Immunoblotting showed that the approximate molecule weight of the antigens recognized by the McAbs were 22kDa,116 kDa and 200 kDa respectively.At least 3 isomorphs of the 22 kDa antigen recognized by 1E1 were found at pI 4.6-6 with 2-D Western blot.Moreover,immunoprecipitation using 125I-labeled S.japonicum SEA demonstrated that only one band corresponding to 30 kDa was recognized by 1E1