Objective To identify the immunologic property of a synthetic peptide Sj97-P22 from paramyosin of Schistosoma japonicum （Sj97）. Methods Twenty-seven female C57BL/6 mice were divided into 3 groups each with 9 mice， Sj97-P22， control peptide and PBS groups， and each mouse was respectively immunized twice （seven days interval） with 100 μg of Sj97-P22， control peptide or PBS， emulsified with equal value of complete Freund′s adjuvant. Seven to ten days after the second immunization， the mouse spleen mononuclear cells were isolated for three-color flow cytometery to detect intracellular cytokines IFN-gamma and IL-4. Then the spleen mononuclear cells were co-cultured with Sj97-P22， control peptide or PBS respectively， and the incorporation rate of 3H-thymidine， as well as the levels of IL-2， IFN-gamma and IL-4 in the cultured cell supernatant， were measured. Results In CD4⁺ T cells， the percentage of IFN-gamma-producing cells in Sj97-P22 group [（8.05±0.54）%] was significantly higher than that of the control peptide group [（4.74±1.04）%] or PBS group [（6.51±0.49）%] （P＜0.05）， while the proportion of IL-4-producing cells was signifi-cantly lower in Sj97-P22 group [（0.60±0.11）%] than that in PBS group [（1.31±0.27）%] （P＜0.05）. Also， compared with control peptide or PBS stimulation， Sj97-P22 was able to effectively stimulate the proliferation with the stimulation index （3.12±1.59） and a higher secretion of IL-2 [（9.13±1.54） pg/ml] and IFN-gamma [（39.75±9.69） pg/ml] of spleen mono-nuclear cells in Sj97-P22-immunized mice （P＜0.05）. Both Sj97-P22 and control peptide were not effective stimulators to the spleen mononuclear cells from mice of PBS group. Conclusion It is highly possible that Sj97-P22 is a Th1-type epitope specific for C57BL/6 mice.