Objective To explore the cause and the interventional treatment of restenosis after percutaneous transhepatic biliary stent.Methods 20 patients with biliary restenosis after percutaneous transhepatic biliary stent placement were collected.According to drainage volume from biliary tract and degree of amelioration of jaundice,post-operation hepatic function,blood,urine and stool routines,ultrasound,CT scan and cholangiography were performed to determine the nature and location of biliary restenosis,and then all cases underwent recanalization with intervention method by the exteriorized drainage tube approach.The China-made nickel-titanium alloy stents with diameter of 10 mm and length ranged from 40 mm to 80 mm were used.Results The biliary restenosis occurred in mid-inferior segment of common bile duct in 9 patients, common hepatic duct in 7 patients and hepatic porta in 4 patients. As regarding the causes of restenosis included tumor compression in 9 cases, angulation in upper segment of stent in 3 cases, obstruction in stent by bile, food or clot in 4 cases, cholangitic stenosis in 2 cases and granulation proliferation in 2 cases.The obstruction in all cases was relived by extraction through drainage tube, drug irrigation,dredging by wire, balloon dialtion or stent replacement, so that the total survival rate was beyond 6 months.Conclusion After percutaneous transhepatic biliary stent placement in treating the malignant biliary obstruction,the rate of biliary restenosis is still high,which should be attached importance to.