Objective To express P38 of Schistosoma japonicum in Escherichia coli BL21 and develop the monoclonal antibodies (McAb) against rSjP38. Methods The recombinant plasmid pET32(a)-P38 was transformed into E.coli BL21(DE3). 1 mmol/L IPTG (isopropyl-beta D-thiogalactopyranoside) was used to induce the expression of the recombinant rSjP38. The rSjP38 was soluble in supernatant after sonication and further purified by His-Ni chromatography. BALB/c mice were immunized with the purified rSjP38 and hybridomas were generated with traditional technique. McAbs were screened by ELISA with limited dilution. The subtype and specificity of McAb were identified by kit and Western blot respectively. Results Eight hybridoma cell lines secreting monoclonal antibodies to rSjP38 were obtained. The subtype of all the 8 McAbs are IgG1. Western blotting showed that the 8 McAbs reacted strongly and specifically with native antigen (P38) of Schistosoma japonicum. Conclusions Eight hybridoma cell lines secreting highly specific McAbs against P38 have been established.