Objective To investigate the history，risk factors for prognosis of malignant biliary stricture （MBS） patients receiving conservative therapy after endoscopic retrograde cholangiopancreatography(ERCP) and to set up a predictive model for overall survival （OS）. Methods MBS patients who underwent ERCP and conservative therapy in Xijing Hospital and PLA No.451 Hospital from January 2009 to December 2013 were enrolled to the present study. Predictive factors associated with OS were identified in the training cohort by stepwise multivariate Cox regression analysis. A predictive model was then developed and externally validated in the validation cohort. Results Between January 2009 and December 2013， 152 and 149 patients were eligible to the training and validation cohort respectively. In the training cohort， tumors were mainly originated from bile duct （33.6％）， pancreas （23.5％） or ampulla （20.4％）. 76.3％ （116／152） patients died during the observation period. The median OS for the training population was 5.0 months （3.9-6.2 months）. CA19-9≥1 000 U／mL， non-ampulla tumor， metastasis， pre-ERCP total bilirubin≥7 mg／dL and hilar stricture were identified as independent predictive factors of poor OS （all P＜0.05）. Based on these factors， the COMTH predictive model was developed. The median OS of patients with COMTH＞8 in the training and validation cohorts were both 3.0 months， which were significantly shorter than those with COMTH≤8 （10.0 and 6.9 months in the training and validation cohorts respectively， both P＜0.001）. Conclusion The prognosis of MBS patients undergoing ERCP is poor. The survival chance of patients with COMTH＞8 is even more dismal.