Abstract： Objective To evaluate the clinical application of the treatment on malignant obstructive jaundice by combination of percutaneous biliary stent placement and 125 I particles intraluminal implanation.Methods As a prospective study , 32 patients with malignant obstructive jaundice who either have no opportunity for radical operations or unwilling to be surgically treated were enrolled to be treated with percutaneous biliary stent placement and 125 I particles intraluminal implanation.Biochemical routine tests , blood routine tests , tumor markers , coagulation function , color ultrasound , CT and magnetic resonance cholangiopancreatography were conducted prior to the operation to obtain general information of the clinical status of the patients and the tumor and the site of obstruction.Percutaneous transhepatic cholangial drainage was performed first under the B -type ultrasound system.After one week , biliary stents were placed under DSA.According to the stent expansion presented by real-time DSA imaging , 125 I particles were implanted simultaneously or afterwards.Routine biochemical tests and cholangiopancreatography under DSA were conducted in one week , one month and three months after the implantation.Variance analysis was performed with repeated measurements to compare the difference of liver function indexes pre -and post-operation.Meanwhile, 125I particle displacement, falling off and stent patency were observed.After three months, the tumor size was measured by CT.Student t-test was used to compare the tumor sizes of pre-and post-operation.Results The symptoms of jaundice resolved and the general physical conditions improved in 32 patients substantially.The total bilirubin level decreased from preoperative level of (302 ±169)μmol/l to the level of (108 ±50)μmol/l at one week following the surgery , and the indirect bilirubin level decreased from preoperative level of ( 250 ±160 )μmol/l to the level of ( 85 ±43 )μmol/l at one week following the surgery(F=76.32,58.23,P<0.01).The maximal diameters of the tumors decreased from preoperative size of (3.78 ±1.14)cm to the size of (3.14 ±1.28)cm at three months following the surgery, and the minimal diameters of the tumors decreased from preoperative size of ( 2.80 ±0.88 ) cm to the size of ( 1.93 ± 1.00)cm at three months following the surgery, and the differences were statistically significant (t=5.11, 6.73,P<0.05).By using Kaplan-Meier survival curve, the average survival periods were ( 9.9 ± 0.7) months.Conclusions Percutaneous biliary stent placement and 125 I particles intraluminal implanation have definite short-term effects in prolonging survival time , stent patency time and improving the living standard of the patients.The technique is safe and simple.It only needs small incision , has no absolute contraindications and can be applied repeatedly .