Objective To assess reduction of adverse drug reaction incidence in patients with colorectal cancer receiving Jianpi herbs combined with chemotherapy. Methods The randomized controlled trials (RCTs) comparing Jianpi herbs combined with chemotherapy were searched through CBMdisc, CJFD, Wangfang Data and PubMed. The search was updated to September 2007. Software RevMan5, provided by Cochrane Library, was used to perform meta-analysis. Results Six RCTs were identified in this systematic review. All the methodology quality of the enrolled RCTs was gaded C. The pooled analysis showed that Jianpi herbs combined chemotherapy significantly reduced the incidences of grade I and grade II leucopenia [grade I with RR= 0.50 and 95%CI (0.31 to 0.80); grade II with RR= 0.37 and 95%CI (0.21 to 0.66)], grade II nausea and vomiting [RR= 0.51, 95%CI (0.31 to 0.84)] compared with routine chemotherapy. There was no statistical difference in reduction of neurotoxicity between the two groups. Conclusion The methodological quality of the RCTs using Jianpi herbs combined with chemotherapy on treating colorectal cancer should be improved. Based on this systematic review, Jianpi herbs combined with chemotherapy may reduce the incidence of mild to moderate adverse drug reaction, such as leucopenia and nausea and vomiting, in patients with colorectal cancer. Well-designed RCTs are needed in the future.