ObjectiveTo explore the effect of Poria cocos on xenograft tumors of gastric cancer SGC-7901 cell line in mude mice. Method①After establishment of xenograft tumor of gastric cancer SGC-7901 cell line, 10 nude mice were equally divided into normal control group and Poria cocos group. The nude mice of each group were gavaged with normal saline (NS) and Poria cocos (0.5 mL) for 32 days, respectively. Tumor volume were measured to draw tumor growth curves and the tumor weight inhibitory rate was calculated with tumor weight (on the 32-day, nude mice were sacrificed to get the xenograft tumors). The expressions of B cell lymphoma 2 (Bcl-2), Bcl-2 associated X protein (Bax), Caspase-3, Caspase-9, and vascular endothelial growth factor (VEGF) were detected by immunohistochemical staining. ②Preparation of drug serum containing Poria cocos. Gastric cancer SGC-7901 cell line were be divided into 2 groups: normal control group and Poria cocos group. Cells of normal control group were treated with serum containing NS, and cells of Poria cocos group were treated with drug serum containing 10% Poria cocos. After 24 hours and 48 hours, Western-blot was used to detect the expressions of Bcl-2 and Bax. ResultsOn 32-day, the volume and weight of xenograft tumors in normal control group〔(2 652.17±225.01) mm3 and (2.48±0.21) g〕were both higher than those of Poria cocos group〔(1 247.56±277.23) mm3 and (1.28±0.28) g〕, P<0.050. The tumor inhibitory rate in Poria cocos group was 48.39%. The results of immunohistochemical staining showed that, compared with normal control group, Poria cocos could down-regulate the expressions of Bcl-2〔(4.20±1.10）score vs. (8.00±1.20) score〕and VEGF〔(3.80±0.45) score vs. (7.80±1.10) score〕, while up-regulate the expressions of Bax〔(7.40±1.34) score vs. (3.00±0.71) score〕, Caspase-3〔(6.60±1.34) score vs. (2.60±0.55) score〕, and Caspase-9〔(7.20±1.79) score vs. (4.00±1.22) score〕, P<0.050. Compared with normal control group (1.72±0.03), the expression value of Bcl-2 was all higher in 24 h-Poria cocos group (0.96±0.04) and 48 h-Poria cocos group (0.77±0.04), P<0.050, and the expression value was higher in 48 h-Poria cocos group than that of 24 h-Poria cocos group (P<0.050). Compared with normal control group (0.15±0.01), the expression value of Bax was higher in 48 h-Poria cocos group (0.55±0.01), P<0.050, but there was no significant difference between the normal control group and 24 h-Poria cocos group（0.19±0）, P>0.050. ConclusionsPoria cocos can restrain the growth of xenograft tumors for gastric cancer SGC-7901 cell line in mude mice, and the mechanism may be related to mitochondrial apoptosis pathway and the inhibition of expression of VEGF.