Abstract: Objective 　To evaluate the efficacy and toxicity of weekly irinotecan combining with CF/ 5-Fu in the domastic patient s with metastatic colorectal cancer. Methods 　CPT-11 125mg/ m² ,5-Fu 500mg/ m², CF 200mg/ m² ;which were used for 4 weeks and ret reated af ter 2 weeks, that was one cycle consisted of 6 weeks. WHO、NCI criterion were used to evaluation. Results 　The 24 patient s with metastatic colorectal cancer were enrolled in this study. Gross efficiency rate was 16. 7 % with 4 cases of PR. The median respond time was 5 months, median time to progression was 6 months, and the median survival time was 11months. Toxic effect s were light . There was no severe delayed diarrhea. Conclusion 　The chemotherapy regimen mentioned above had better effective and less toxic effect s, suitable for the metastatic colorectal cancer.