ObJective: To observe influence of Yiqi Fuyuan Tang(YQFYT) combined with chemotherapy on apoptosis of colorectal cancer Lovo cells and the related molecular mechanism. Method: Experiment was divided into 5 groups: YQFYT-containing serum group

chemotherapeutic drugs-containing serum group

YQFYT+chemotherapeutic drugs-containing serum group

serum control group and blank control group. Apoptosis of colorectal cancer Lovo cells was investigated with AO/EB double fluorescent staining and single staining of Annexin V-FITC for each group. Expression of apoptosis proteins Bcl-2 and Bax of Lovo cell was determined. Result: The results indicated that YQFYT-containing serum had action of inducing apoptosis in colorectal cancer Lovo cells

and enhanced the effects of induced apoptosis of chemotherapeutic drugs. Western blot assay showed that:①Bcl-2

Bax protein expression was not significantly different between serum control group and blank control group; ②There was significant difference between treatment groups (P<0.01). The order from weak to strong of the Bcl-2 protein expression was as follows: YQFYT+ chemotherapeutic drugs-containing serum group

chemotherapeutic drugs-containing serum group

YQFYT-containing serum group

serum control group. The order for bax protein expression was Just the opposite. Conclusion: Serum YQFYT-containing serum has action of inducing apoptosis in colorectal cancer Lovo cells

and can enhance the effects of chemotherapeutic drugs for inducing apoptosis. Down-regulation of Bcl-2 protein expression and up-regulation of Bax protein expression might be one of the main mechanisms for apoptosis of Lovo colon cancer cells.