Objective:To investigate the expression of RASAL3 in intrahepatic cholangiocarcinoma (iCCA) and the mechanism of promoting iCCA development.Methods:Tumor and paracancerous tissues were collected from 185 iCCA patients, the expression of RASAL3 was detected by immunohistochemistry, RT-qPCR and Western blot. The expression of RASAL3 and FXYD6 mRNA and protein in human cholangiocarcinoma cell line and human bile duct epithelial cells were detected with RT-qPCR and Western blot, the cell proliferation was detected with CCK-8 assay, and the activity of Na +-K +-ATPase was also detected. Results:RASAL3 was highly expressed in cholangiocarcinoma tissues and cell lines; Survival analysis showed that RASAL3 overexpression was associated with poor prognosis of cholangiocarcinoma( P<0.05) and knockdown of RASAL3 inhibits the proliferation of cholangiocarcinoma cells; Silencing RASAL3 decreases the expression of FXYD6 inhibiting the activity of Na +-K +-ATPase. Conclusion:RASAL3 is up-regulated in human cholangiocarcinoma, which can promote the occurrence and development of cholangiocarcinoma by activating FXYD6 and affecting Na +-K +-ATPase activity.