Objective To investigate the effect of percutaneous transhepatic biliary radiofrequerncy (RFA) combined with biliary selfexpandable metallic stent (SEMS) implantation on laboratory indexes in patients with malignant biliary obstruction. Methods 82 patients with malignant biliary obstruction treated in Yibin First People's Hospital were selected as the subjects. They were randomly divided into the control group (treated with SEMS, n=41) and the combined group (treated with RFA combined with SEMS, n=41) according to the order of admission. Laboratory indexes［total bilirubin (TBIL), alanine aminotransferase (ALT), γglutamyl transpeptidase (γ-GT), albumin］, postoperative stent patency rate, survival and the incidence of complications in two groups were observed. Results There was no significant difference of TBIL, ALT, γ-GT and albumin between the two groups before operation (P＞0.05). After operation, levels of TBIL, ALT and γ-GT decreased significantly while albumin increased significantly in two groups, and changes of abovementioned indexes in combined group were greater than those in the control group (P＜0.05). The patency rates of stent in the combined group at 9 months and 12 months after operation (9268% and 8780%) were significantly higher than those in the control group (73.17% and 68.29%) (P＜0.05). There was no significant difference of survival rate between the two groups at 6 months after operation (P＞0.05), but the survival rate of the combined group was significantly higher than that of the control group at 12 months after operation, and the average survival time of the combined group was significantly longer than that of the control group (P＜0.05). There was no significant difference in the incidence of postoperative complications between the two groups (χ2=0.497, P＞0.05). Conclusion RFA combined with SEMS has more advantages over SEMS alone in the treatment of malignant biliary obstruction, in terms of reducing laboratory liver function indexes, increasing albumin levels, improving stent patency rate and prolonging the survival time.