Abstract: Objective:To observe the effects and side effects of irinotecan plus fuorouracil/leucovorin in treatment of patients with advanced colorectal cancer.Methods:Irinotecan 150-180 mg/m² intravenous drip (90 min),fuorouracil 500 mg bolus and leucovorin 500 mg intravenous drip (2 h) were administered on day 1;1 250-1 500 mg/m² was injected intravenously for 44 h,at least 2 cycles.Results:All the 20 patients received 73 cycles of the chemotherapy,and 19 patients were assessable.Complete remission was observed in 1 case,partial remission in 6 cases,disease stable in 5 cases and disease progress in 7 cases.The main adverse reactions were leucopenia,diarrhea,nausea and vomiting.No chemotherapy related death was noted.Conclusions:The combination therapy of irinotecan plus fuorouracil/leucovorin is effective for treatment of patients with advanced colorectal cancer,and the adverse reaction can be obviated or controlled.This therapy can be widely used in clinical application.