To clarify the benefits and risks of postoperative adjuvant chemotherapy (ACT) compared with surgery alone in patients with stage II/III colorectal cancer, a literature search was conducted using the PubMed and Embase databases with a deadline of Dec 29, 2021. The search keywords was colorectal cancer. The endpoint for this study were OS and DFS. A total of 34 studies with 71 treatment arms and 33069 subjects were included in the analysis.