Objective To compare the short-term effects of FOLFOXIRI and SOX chemotherapy regimens in treatment of advanced colorectal cancer. Methods A retrospective study was conducted. The clinical data of 71 patients with advanced colorectal cancer admitted from January 2013 to January 2015 in Jingmen Second People's Hospital were analyzed. According to the different chemotherapy regimens, the patients were divided into two groups. The SOX group was treated with SOX chemotherapy regimen (oxaliplatin+S-1), and the FOLFOXIRI group was treated with FOLFOXIRI chemotherapy regimen (oxaliplatin + irinotecan + 5-fluorouracil). After 4 courses of treatment, the clinical efficacy and adverse reactions were compared between the two groups. The patients were followed up for 6-24 months, and the survival of the two groups was compared by using Kaplan-Meier method. Results After 4 courses of treatment, in the FOLFOXIRI group, 16 cases were partial remission, 11 cases were stable disease, 10 cases were disease progression; in the SOX group, 15 cases were partial remission, 10 cases were stable disease, 9 cases were disease progression; there was no significant difference in the clinical efficacy between the two groups (Z = 0.069, P > 0.05). In the FOLFOXIRI group, the objective response rate was 43.24% (16/37), the clinical control rate was 72.97% (27/37); in the SOX group, the objective response rate was 44.12% (15/34), the clinical control rate was 73.53% (25/34); there were no significant differences between the two groups (χ2 values were 0.005 and 0.003, both P > 0.05). In the FOLFOXIRI group, the 1-, 2-year survival rates were 83.78% (31/37) and 29.73% (11/37); in the SOX group, the 1-, 2-year survival rates were 85.29% (29/34) and 38.24% (13/34); there were no significant differences between the two groups (χ2 values were 0.031 and 0.573, both P > 0.05). In the FOLFOXIRI group, the median progression free survival time was 9.4 months, and the median overall survival time was 19.2 months; in the SOX group, the median progression free survival time was 11.6 months, and the median overall survival time was 20.3 months; there were no significant differences between the two groups(χ2 values were 0.85 and 0.573, both P > 0.05). The incidence rates of leukocyte depletion and diarrhea of FOLFOXIRI group were significantly higher than those of SOX group (Z values were 2.252 and 2.214, both P < 0.05). Conclusion FOLFOXIRI regimen has similar efficacy with SOX regimen in treatment of advanced colorectal cancer, but SOX regimen is more tolerant. Key words: Colorectal neoplasms; Antineoplastic combined chemotherapy protocols; Prognosis; Survival analysis