Objective:To investigate the effect of Feiai Ping on inducing cell apoptosis of Lewis lung cancer mouse.Methods:We chose the cell strain of Lewis lung cancer mouse,inoculated the cell strain subcutaneously.After building the tumor animal model successfully,we divided the animal into Saline control group and Feiai Ping treating group.Using the method of light microscope(LM) and electron microscope(EM) to observe the morphology.Results:Feiai Ping treating group has 16 episode mice,while the control group has 20 samples.To be compared with the control group,the experimental group has following characteristics:the tumor ball and the cell volum are smaller,the atypia is not evident,and the pathological karyokinesis and interstitial blood vessel are fewer.It has necrosis and infiltration of lymphocyte.Through the observation of EM,we found the formation of apoptotic body.In addition,the Feiai Ping can activate the proliferation of lymphocyte.There are many lymphocytes between the tumor cells and the lymphocytes invade the tumor cells to destroy the tumor cells.Conclusion:Feiai Ping has the function of anti-lung cancer which mechanism maybe induce the tumor cell apoptosis of the Lewis lung cancer mouse and activate the proliferation of lymphocyte.