Objective To evaluate the accuracy of confocal laser endomicroscopy (CLE)in primary bile reflux gastritis (BRG).Methods From November 10th to December 15th,2015 ,55 patients underwent CLE examination and preliminarily diagnosed as BRG with traditional white-light endoscopy were enrolled.CLE score standard was designed.Dixon pathologic score was considered as gold standard. Receiver operating characteristic (ROC)curve was drawn to evaluate the accuracy of CLE score in BRG diagnosis.Sensitivity,specificity and 95 % confidence interval (CI )were calculated.Kappa analysis was performed to assess the inter-observer agreement of CLE score.Results According to Dixon pathologic score standard,29 patients (52.7%)were diagnosed as primary BRG among the 55 enrolled patients. Among the 42 Helicobacter pylori (H .pylori )negative patients,the area under receiver operating characteristic curve (AUC)of CLE in BRG diagnosis was 0.90 (95 %CI 0.81 —1 .00).Taking CLE score over six as the cut-off value for diagnosis,the sensitivity and specificity was 84.00% (95 %CI 65 .35 %—93.60%)and 82.35 % (95 %CI 58.97%—93.81 %),respectively.The Kappa value for inter-observer agreement in BRG diagnosis was 0.60 (95 %CI 0.24—0.95).Conclusion Primary BRG can be accurately diagnosed by CLE in H .pylori negative patients with high sensitivity and specificity.