Objective To discuss the influence of Yiqi Bushen Formula （Formula for replenishing qi and tonifying the kidney） on the ability of invasion and metastasis of gastric cancer cells SGC-7901. Methods The gastric cancer cells SGC-7901 were inoculated into the RPMI-1640 culture solution. Yiqi Bushen Formula decoction was prepared to 7 final concentrations as 1

2

4

8

16

32

and 64mg/ml. The cancer cells

taken as the blank control group

were put into the 96-hole plate. Each dose of the Formula decoction was applied to the 6 parallel holes of the plate. The procedure was repeated for 3 times. Cells were incubated in the incubator at 37℃ and 5%CO2 for 48h. The inhibition rate of proliferation of SGC-7901 cells by the different concentrations of Yiqi Bushen Formula was detected with the MTT method. The activity of gene expressions of matrix metalloproteinase-2 （MMP-2） and its inhibitory enzyme-2 （TIMP-2） of SGC-7901 cells were measured with the RT-PCR method. Results The Formula decoction of different concentrations had certain inhibiting action on SGC-7901 cells

but the concentrations 16mg/ml and 32mg/ml functioned better

the inhibition rate being 53.17% and 56.47% respectively. Compared with blank control group

the difference was statistically significant in the MMP-2 of the 32mg/ml group （P<0.05）

and the MMP-2 mRNA expression of the 16mg/ml group was also down-regulated

but the difference was not statistically significant （P>0.05）. Conclusion Yiqi Bushen Formula is effective in inhibiting the ability of invasion and metastasis of gastric cancer cells SGC-7901

and the result of concentration 32mg/ml was the best.