Abstract: Coumarins are a class of compounds with multiple biological activities such as antitumor, anti-inflammatory, anti-virus, and anti-bacterial properties. The anti-tumor activity is of high selectivity and low toxicity, however, the clinical use of natural coumarins is often restricted by their less bioactivity, poorer water-solubility and lower bioavailability. Therefore, the structural modification and structure-activity relationship of coumarins have become a research hotspot. The recent progress in the studies of coumarin derivatives with antitumor activities is reviewed in this paper.