Objective To evaluate intra-biliary tunnel electro-resection and aspiration approach during ERCP for severe biliary stricture. Methods A total of 14 patients with severe benign or malignant biliary stricture, which failed in previous ERCP, were recruited. First the guide wire was passed gently through the narrow segment under fluoroscopy, then the double-lumen needle knife was placed near the stricture and wire cutter was protruded. The tunnel electro-resection and aspiration was performed along the guide wire until the narrow segment could be passed through under fluoroscopy by the expanding balloon dilator for the following procedures. Results Of 14 patients with severe biliary strictures, electro-resection and aspira- tion procedure were successful in 12 (85.7%). Metal stems were implanted in all 7 patients with malignant biliary strictures. Plastic stents were placed after balloon dilatation in 5 patients with benign stenosis. Three out of 5 patients received double plastic stents, while the two others only needed a single plastic stent. The procedure was failed in 2 patients ( 14. 3% ) with malignant biliary strictures as hilar cholangiocarcinoma invaded the left and right hepatic duct, forming a right angle in biliary stenosis, so that needle knife could not go through, and the following procedure was aborted. There were no severe complications like massive bleeding, perforation or death observed. Conclusion The intra-biliary tunnel electro-resection and aspiration approach can significantly increase the success rate of ERCP in severe biliary strictures. Key words: Cholangiopancreatography, endoscopic retrograde; Bile ducts obstruction