Ganoderma lucidum (G lucidum) is a medicinal fungus with a variety of biological activities. It has long been used as a folk remedy for promotion of health and longevity in China and other oriental countries. The most attractive character of this kind of medicinal fungus is its immunomodulatory and anti-tumor activities. Large numbers of studies have shown that G lucidum modulate many components of the immune system such as the antigen-presenting cells, NK cells, T and B lymphocytes. The water extract and the polysaccharides fraction of G lucidum exhibited significant anti-tumor effect in several tumor-bearing animals mainly through its immunoenhancing activity. Recent studies also showed that the alcohol extract or the triterpene fraction of G lucidum possessed antitumor effect, which seemed to be related to the cytotoxic activity against tumor cells directly. Preliminary study indicated that antiangiogenic effect may be involved antitumor activity of G lucidum.