This paper reviewed the advances on effective constituents and biological activities of coumarins in recent ten years. Coumarins are a group of important natural compounds, and have been found to have multi-biological activities such as anti-HIV, anti-tumor, anti-hypertension, anti-arrhythmia, anti-osteoporosis, assuaging pain, preventing asthma and antisepsis. Therefore, further investigation should emphasize on improving techniques for extraction and separation, searching the effective precursory compound, and synthesizing and screening out courmarin derivatives with high activity and low toxicity.