Objective To study the effect of splenectomy on the anti-tumor immunity in rats with induced hepatocellular carcinoma (HCC). Methods At the second and fourth month of the induced HCC, the NK cell activity, TNF-α level and total lymphcyte in blood were measured in the group of splenectomy and the control group. Results There were no different in the total lymphcyte and TNF-α in the blood in two groups, but there were significant difference in the NK cell activity between the group of splenectomy and the control group (Ｐ＜0.05). Conclusion There are some change in the anti-tumor immunity after splenectomy in rats, in which NK cell activity is at low level continuously. TNF-α isn′t affected after the second month after splenectomy.