Aspirin has been widely used as an antipyretic analgesic drug. More and more evidences have shown that aspirin may be play some role on anti-tumor. In this article, we reviewed the research history of aspirin in the treatment and prevention of cancer. Many epidemiological and clinical studies have shown that aspirin can reduce the risk of a variety of malignant tumors and reduce cancer mortality. In addition, we discuss the specific mechanisms of aspirin in the anti-tumor effects. It has been found that aspirin mainly depends on the COX pathway and non-COX pathway to inhibit tumor cell growth and to curb tumor development. In this article, clinical studies and anti-tumor mechanism studies published in recent years are reviewed.