Abstract: objective To investigate the changes of the proportion of type-2 innate lymphoid cell （ILC2）in mice infected with Clonorchis sinensis, and to explore its possible mechanism of action. Methods The Balb/C mouse were sacrifice d at 14d, 28d and 56d after infect ed with Clonorchis sinensis, then the liver lymphocytes were isolated and the proportion of lin-ST2+ cells were detected by flow cytometry, while the proportion of IL-7Rα+, Sca-1+, ICOS+, Sca-1+ cells were analyzed to ILC2. Results Compared with the control group, the proportion of Lin -ST2+ (ILC2) in CD45 + cells was significantly increased at 14 d, 28 d and 56 d after infection (P<0.05); as the infection continued, the proportion decreased slightly, and continued until the end of the experiment. The proportion of IL-7Rα+, Sca-1+, ICOS+, Sca-1+ cells in ILC2 increased significantly at 28 d and 56 d after infection, with statistical differences (P<0.05). Conclusion ILC2 increase significantly after infection of Clonorchis sinensis, they play a n important role in the anti-infection of Clonorchis sinensis