Oxymatrine is one of the key components extracted from Sophora flavescens, a leguminous plant grown in China, Japan, and some European countries. It has attracted much attention because of its low toxicity and side effects. Extensive research over the past decades have revealed various important pharmacological activities of oxymatrine under in vitro and in vivo conditions, including anti-inflammation, immunoregulatory, antihepatitis virus infection, antihepatic fibrosis, antianaphylaxis, and other immune regulation. Oxymatrine has been extensively studied for their cancer chemopreventive potential against various cancers, for instance, human pancreatic cancer, gastric cancer, breast cancer, lung cancer, osteosarcoma, and leukemia. However, the precise mechanisms underlying the anticancer activity of oxymatrine are largely unknown.