To study the efficacy of garlic YZD composition in the treatment of gastric precancerous lesions,and to further clarify the mechanism of garlic YZD composition in the treatment of gastric precancerous lesions.Methods:The rats were randomly divided into 2 groups：a control group(14 rats) and a model group(144 rats).After 22 weeks of modeling,the rats were randomly divided into 6 groups：a model group,a garlic oil control group,a Weifuchun control group,a garlic YZD composition high,a medium and low dose groups,with 24 rats in each group.They were killed after 13 weeks of continuous administration.After taking the material,the pathological changes of gastric mucosa were observed under light microscope.At the same time,the levels of three tumor markers CEA,CA199 and CA724 in the centrifuged plasma of rats in each group were detected by electrochemiluminescence.Western Blotting and Real-time PCR were used to detect the protein and mRNA expression of TGF-β1 and Smad4 in gastric tissues of rats with gastric precancerous lesions.Results:1)High dose group of garlic YZD composition(2.38 g/kg) could significantly improve the pathological changes of gastric mucosa in rats with gastric precancerous lesions.2)High dose group of garlic YZD composition(2.38g/kg) can significantly reduce the levels of CEA,CA199 and CA724 tumor markers in serum of rats with gastric precancerous lesions.3)High dose group of garlic YZD composition(2.38g/kg) can down regulate the expression level of TGF-β l mRNA and its protein,but up regulate the expression level of Smad4 mRNA and its protein.Conclusion:High dose group of garlic YZD composition(2.38 g/kg) can significantly improve the pathological changes of gastric mucosa in rats with gastric precancerous lesions,reduce the level of serum tumor markers,regulate the protein expression of TGF-β1 and Smad4,so as to correct the abnormal changes of TGF-β1/Smads signal transduction pathway,and effectively treat the precancerous lesions of gastric cancer.