〔Abstract〕 Objective To detect the differences in the expression of Yes-associated protein(YAP) in non-cardia gastric cancer and normal gastric tissue and analyze the associations between single nucleotide polymorphisms(SNP) in the YAP gene andits protein expression,and to preliminarily discuss the correlationbetween YAP and the development of non-cardia gastric cancer,so as to provide new ideas for the prevention and treatment of non-cardia gastric cancer.Methods 126 casesofnon-cardia gastric cancer tissues and 104 cases of paracancerous normal tissues were collected and set as case group and control group,respectively. Immunohistochemical SP assay was used to detect the expression of YAP in non-cardia gastric cancer tissues and adjacent normal tissues. Taqman method was used for genotyping. The unconditional logistic regression method was used to calculate the odds ratio(OR) and its 95%confidence interval(CI) to detect the associations between YAP SNPs and the expression of YAP protein under Codominant,Dominant,Overdominant,Recessive,and Log-additive genetic models.Results The expression of YAP protein in non-cardia gastric cancer tissues was significantly higher than that in normal gastric tissues(P<0. 001).The expression level of YAP protein was negatively correlated with the degree of tumor differentiation(P<0. 05).There was no correlationbetween the expression level of YAP protein and gender,age,lymph node metastasis and tumor size respectively(P>0. 05). No associations were found between SNP rs11225163 and rs1820453 and the expression of YAP protein under Codominant,Dominant,Overdominant,Recessive and Log-additive genetic models.Haplotype was constructed by Haploview 4. 2 software,and the association between haplotype and YAP protein expression was analyzed.Conclusion YAP may be involved in the development of non-cardia gastric cancer.