Objective: To analysis the clinical value of ultrasound-guided percutaneous pyelostomy in the treatment of malignant obstructive renal failure. Methods: 72 cases of obstructive renal failure caused by malignant tumor accepted ultrasound-guided percutaneous pyelostomy. The postoperative efficacy was observed by serum creatinine(Cr) and urea level. Results: 72 patients were one-time successfully punctured. The successful rate of nephrostomy was 100%. The follow-up period was four weeks. days and put indwelling catheter without serious complications. The renal functions recovered to some extent after operation. The renal functions of 69 patients were improved obviously in one week except 3 patients, in whom renal functions were improved in two weeks. The effective rate reached 95.8% in one week. The decrease range of Cr was 120-270umol/L. The decrease range of BUN was 3.9-8.1mmol/L. 5 patients occurred minor complication(6.9%). Conclusion: Ultrasound-guided percutaneous pyelostomy can effectively improve the renal failure caused by malignant tumor in short time.