Objective:To study the role of CD8+T cell subsets in the development of liver immunopathology after Schistosoma japonicum (S japonicum)infection. Methods:Splenocytes were prepared from spleens of mice with S. japonicum infection at 0 and 8 weeks,and the proportions of Tc1,Tc2 and CD8+T regulatory cells in T cells were determined by FACS. The relationship between CD8+T cell subsets and liver immunopathology were analyzed. Results:Compared to the control group,the spleen mononuclear cells (MNC)in S. japonicum infected mice were increased significantly (P < 0.001). In addition,the proportions and the absolute numbers of T cells and CD8+T cells in spleen of S. japonicum infected mice were significantly increased(all P < 0.05). Furthermore,the proportions of Tc1,Tc2 and CD8+T regulatory cells were significantly increased at 8 weeks post-infection(all P values < 0.05)and the proportions of Tc2 cells increased more significantly than Tc1 cells. Multiple linear regression analysis showed that Tc2 and regulatory CD8+T cells were the main factors affecting liver immunopathology during S. japonicum infection. Conclusion:Tc1,Tc2 and CD8+ T regulatory cells in splenocytes increased significantly after S. japonicum infection. Tc2 and regulatory CD8+ T cells play critical roles in promoting and inhibiting the liver immunopathology,respectively.