Objective：To observe the expression and clinical significance of Yes-associated protein（YAP） gene and protein in human renal carcinoma tissues. Methods：The expressions of YAP mRNA were measured by reverse transcription-polymerase chain reac－tion （RT-PCR） and the expressions of YAP protein were detected by immunohistochemistry in 42 cases of human renal carcinoma tis－sues and their corresponding adjacent non-malignant tissues. Results：The positive expression rates of YAP mRNA in renal carcino－ma tissues and adjacent non-malignant tissues were 88.10% and 14.29% respectively. The positive expression rate of YAP protein was higher in renal carcinoma tissues than in adjacent non-malignant tissues（95.23% vs. 30.95%），with statistical differences（P<0.05）. Conclusions：The expression of YAP might be associated with the generation and development of renal carcinoma and its abnormal expression can provide references for the diagnosis and treatment of renal carcinoma. Especially，it can establish the theoretical basis for inducement of cell apoptosis and gene therapy of renal carcinoma.