To observe tumor inhibiting effect of Weifu Formula in nude mice with human gastric cancer BGC-823 and its effects on gene expression of C-Myc and hTERT，and to evaluate the effects of Weifu Formula and its possible mechanism of action.Methods:The nude mouse model with human gastric cancer BGC-823 was established.A total of 40 tumor-bearing mice were performed successful modeling for nude mice with subcutaneous xenograft tumor of gastric cancer.They were randomly divided into 5 groups(n=8)：model group，low dose Weifu Formula group，high dose Weifu Formula group，5-Fu group，and 5-Fu combined with Chinese materia medica group，with continuous administration for 4 weeks.Long diameter and short diameter of tumor were recorded every 7 d，tumor volume was calculated and tumor growth curve chart was drawn.All the tumor-bearing mice were killed after 4 weeks of administration，and the subcutaneous xenograft tumor was resected.The tumor was weighed and tumor inhibition rate was calculated.Protein expression of C-Myc and hTERT in tumor tissue was detected by immunohistochemistry.Results:1)Weifu Formula had obvious inhibiting effect on xenograft tumor in nude mice with human gastric cancer BGC-823 and there was dose-effect relationship between different doses.The tumor inhibition rates in the low dose Weifu Formula group，the high dose Weifu Formula group，the 5-Fu group and the 5-Fu combined with Chinese materia medica group were 21.06%，45.89%，30.65% and 59.42%，respectively.Efficacy in the 5-Fu combined with Chinese materia medica group was the best.2)In terms of tumor weight compared with the model group，the tumor weight in each medicine group showed different degrees of decrease(P<0.05).Among them，the decrease in the 5-Fu combined with Chinese materia medica group was significant.3)The tumor growth curve chart showed that the tumor volume in each medicine group was decreased to some extent compared with the model group(P<0.05).4)In comparison with the model group，the immunohistochemical results showed that the expression levels of C-Myc and hTERT proteins were decreased in each medicine group(P<0.05)，among which the decrease in the 5-Fu combined with Chinese materia medica group was the most obvious.Conclusion:Weifu Formula can inhibit the growth of subcutaneous xenograft tumor in BALB/c-nu nude mice with human gastric cancer BGC-823 cell，which may be related to the down-regulation of C-Myc and hTERT protein expression.And it has synergistic effect when combining with 5-Fu for medication，indicating that Weifu Formula has certain efficacy in human gastric cancer.