Objective The occurrence and progression of renal cell carcinoma ( RCC) is complicated process associated with DNA abnormal methylation , histone modification , and Wnt signaling pathway .This study aimed to investigate the expression of histone methylase SET8 in RCC, its relationship with the Wnt signaling pathway , its action mechanism in RCC , and its clinical significance . Methods We selected 50 cases of RCC treated by radical nephrectomy , detected the expression of SET 8 in the RCC and adjacent noncancerous kidney tissues by immunohistochemical EliVision two-step staining with β-catenin.We compared the expression levels of SET8 and β-catenin in the two types of tissue and analyzed their relationship with the patients′clinical information and the pathologic stage and grade of tumor as well as the correlation between the SET 8 andβ-catenin expressions . Results SET8 was mainly express in the cytoplasm of the RCC and noncancerous kidney tissues , partially in the cell membrane and nucleus , while theβ-catenin protein chiefly in the cell membrane of renal tubular epithelial cells in the normal kidney tissue .The expression levels of SET 8 and β-catenin in the RCC tissue were closely related to the TNM stage and tumor grade (P<0.05).The positive expression of SET8 in the RCC tissue (76%[38/50]) showed no significant difference from that in the ad-jacent noncancerous kidney tissue (66% [33/50]) (P>0.05), but that of β-catenin was remarkably higher in the former (68%[34/50]) than in the latter (4%[2/50]) (P<0.01).There was a positive correlation between the positive expression of SET 8 and the abnormal expression of β-catenin (r=0.219, P<0.05). Conclusion SET8-activated H4K20me-1 controls the activation and abnormal activities of the Wnt signaling pathway , affects the gene transcription and cell activity , and participates in the occurrence , progression, and distant metastasis of RCC .