Abstract: AIM:To compare the efficacy and adverse reaction of oxaliplatin (L-OHP)in first-line chemotherapy of metastatic colorectal cancer(MCC)combined with infusional 5-fluorouracil (5-FU)and Calcium folinate (CF)administered every 2 weeks (FOLFOX4regimen)or every 3 weeks.METHODS:66previously untreated MCC patients were randomized in two chemotherapy regimen group :grouop A, oxaliplatin 85 mg/m² on first day, CF 200 mg/m² infusion 2h followed by bolus 5-FU 400 mg/m² and a 22h infusion of 5-FU 600 mg/m², repeated for 2consecutive days every 2 weeks.group B, oxaliplatin 130 mg/m² on first day, CF 200 mg/m² infusion 2h followed by a 4-6h infusion of 5-FU 375-425 mg/m², repeated for 5 consecutive days every 3 weeks.RESULTS:The two regimens have similar efficacy, the response rate of group A and B was 42.9% and 38.7% respectively (P>0.05).The adverse reaction rates of the two regimen were no statistical difference.CONCLUSION:The 2-week regimen and the 3-week regimen of L-OHP combined with 5-FU/CF have the same efficacy inMCC patients.

Key words: oxiplatin, 5-fluorouracil and calcium folinate, the first-line chemotherapy, metastatic colorectal cancer, 2-week regimen, 3-week regimen