〔Abstract〕 To summarize the diagnosis and treatment of acute renal failure caused by ureteral obstruction at different time. Retrospective analysis of 85 cases of acute renal failure caused by ureteral obstruction. The obstruction was successfully relieved in 85 cases, and the renal function was normal in 62 cases one week after operation. The decrease of urine volume, creatinine and urea nitrogen in 24 hours after operation in the group with obstruction≤1 week was significantly greater than that in the group with obstruction>1 week, and there were no dialysis patients;the number of positive cases in the group with obstruction≤1 week was significantly higher than that in the group with obstruction>1 week.The shorter obstruction time of acute renal failure caused by ureteral obstruction, the better prognosis after effectively removing the obstruction.