Ginseng, Panax ginseng (C. A. Mey.), is a well-known Chinese traditional medicine in the Far East and has gained popularity in the West during the last decade. There is extensive literature on the chemical constituents and bioactivities of ginseng. In this paper we compiled the chemical constituents isolated and detected from ginseng including polysaccharides, ginsenosides, peptides, polyacetylenic alcohols, fatty acids, etc. Meanwhile we summarized the biological activities of ginseng, which have been reported over the past few decades, including: anti-aging activity, anti-diabetic activity, immunoregulatory activity, anti-cancer activity, neuroregulation activity, wound and ulcer healing activity, etc. Nevertheless, further studies to exploit other kinds of constituents and new biological activities of ginseng are still necessary to facilitate research and development in the future.