Abstract: Objective The purpose of this study is to evaluate the association of postoperative adjuvant chemotherapy and clinical prognosis, as well as the relative risk factors. Method Case-control studies assessing the postoperative adjuvant chemotherapy and clinical prognosis or relative risk factors for stage Ⅱ colorectal cancer were searched from databases between March 2007 and March 2018. Overall survival （OS）, recurrence-free survival （RFS） were calculated and systematically analyzed by forest plot in RevMan 5.3. Result 20 case-control studies which covered a total of 289 684 patients were contained in this meta-analysis. The result of this study indicated that regular postoperative adjuvant chemotherapy for stage Ⅱ colorectal cancer would not improve OS（OR=0.98,95%CI 0.84~1.16, P=0.85）or RFS（OR=0.85,95%CI 0.69~1.05, P=0.13）. However, when relative risk factors taken into consideration, such as T4 stage, poor differentiation or undifferentiation, intestinal obstruction or perforation, lymph or vascular or peripheral nerve invasion, inadequate sampled lymph nodes, patients would significantly benefit from postoperative adjuvant chemotherapy as a whole（P<0.05）. For the chemotherapy regime, adding of Oxaliplatin into conventional 5-Fluorouracil would not affect the OS（OR=0.99,95%CI 0.80~1.22,P=0.92）, but do improve RFS（OR=0.81,95% CI 0.68~0.96,P=0.02）, which significantly decrease the postoperative recurrence. Conclusion For stage Ⅱ colorectal cancer patients, after curative operation, chemotherapy does not need to apply routinely, but need to use in those with risk factors. Although Oxaliplatin+5-Fluorouracil+Leucovorin （FOLFOX） does not significantly improve OS, the better RFS suggests a better control of postoperative recurrence.