Abstract: Objective:To observe the efficacy and safety of irinotecan combined with raltitrexed in the second-line chemotherapy of advanced colorectal cancer.Methods:Twenty-two patients with advanced colorectal cancer were treated with the second-line chemotherapy after the first-line treatment failure.The patients were treated with 180 mg/m² of irinotecan by intravenous infusion for 1 h on the first day,and 3 mg/m² of raltitrexed by intravenous infusion for 15 minutes on the second day,21 days as a cycle.The efficacy and safety were evaluated every 2 cycles.Results:The short-term efficacy of all cases was evaluated.The complete response in 1 case,partial response in 4 cases,stable disease in 11 cases and progressive disease in 6 cases were found.The objective response and disease control rates were 22.7% and 72.7%,respectively.The median time of tumor progression and median overall survival time were 5.0 and 11.8 months,respectively.The neutrophilopenia and diarrhea were serious adverse reactions,the incidence rates of those were 13.6% and 4.5%,respectively.Conclusions:The irinotecan combined with raltitrexed in the second-line chemotherapy of advanced colorectal cancer is high efficacy,and the adverse reactions can be tolerated,which is worthy of wider application.