In this study, the inhibitory effect of Yifei Kangliu Yin (YFKL) was observed on growth of LAX-83 human lung adenocarcinoma in naked mice. It was found that the YFKL could suppress the tumor growth significantly with a suppression rate of 45.59%. It was also found that positive expression of Ki-67 and cell proliferation significantly decreased, c-myc changed from positive to weak positive and P53 from positive to negative in the YFKL treated group. It suggested that the inhibitory effect of YFKL on proliferation of cancer cells might be realized by way of changing the oncogenetic expression of cancer, so as to influence the cell proliferation directly.