Abstract: Objective To investigate the effect of microwave ablation(MA) of hepatocellular carcinoma(HCC),which influences the proportion of immunocytes and cytokine-secreting of the tumor- bearing mice. Methods A HCC model of C57BL/6J mouse was established by subtaneous inoculation of syngeneic Hepa1-6 cells,the tumors were treated with MA or resection,before and after the treatments, the proportion(%)of CD4+,CD8+,NK1.1+cell of peripheral blood,and the concentration(ng/L) of IL-2, IL-10,IL-12 and IFN-γof plasma of the hosts were determined with flow cytometry and ELISA,respectively. Results Compared with group normal,in group 2 ～ 3 weeks tumor- bearing, the proportion of the immunocytes detected,and the concentration of the examined cytokoines were not markedly altered.For comparison of group MA with that tumor-bearer ,CD4+ ,CD8+cells and IL-2、IL-10 of the former were not obviously different from that of the latter , NK1.1+ cell, IL-12 and IFN-γ of the former markedly higher than that of the latter (P <0.05, P <0.01, P <0.01,respectively，n = 6).Compared with the group tumor-bearing, the immuocytes and cytokines of the group resection were not significantly changed . The NK1.1+cells and IL-12 of group MA were markedly higher than that of group resection(P <0.01 and P <0.05,respectively，n = 6 ),but there was no obvious difference for other immune cells and cytikines in the two groups. Conclusion The MA of the mouse HCC may induce Th2/Th1 deviation and markedly enhance the proportion of NK cells of the tumor-bearer.