Corilagin, a gallotannin, is one of the major active components of many ethnopharmacological plants. It was isolated from Caesalpinia coriaria (Jacq.) Willd. (dividivi) by Schmidt in 1951 for the first time. In the past few decades, corilagin was reported to exhibit anti-tumor, anti-inflammatory and hepatoprotective activities, etc. However, little attention was paid to its pharmacological properties due to the complicated and inefficient extract method. In recent years, with the development of extraction technology corilagin was much easier to obtain than before. Thus, people return to pay attention to its anti-tumor, hepatoprotective, and anti-inflammatory activities, particularly as an anti-tumor agent candidate. Our research team had focused on the distribution, preparation and anti-tumor activity of corilagin since 2005. We found corilagin showed good anti-tumor activity on hepatocellular carcinoma and ovarian cancer. What’s more, corilagin showed a low level of toxicity toward normal cells and tissues. Due to the extensive attention that corilagin has received, we present a systematic review of the pharmacological effects of corilagin. In this review, we summarized all the pharmacological effects of corilagin with a focus on the molecular mechanism of anti-tumor activity and show you how corilagin affected the signaling pathways of tumor cells as well as its physicochemical properties, distribution and preparation methods.