During the course of the last two decades, the health effects of tea and its catechins have been docmnented in nmnerous scientific studies and the scientific basis of these effects has been elaborated. Professor Kuroda and Dr. Hara provide in this volmne a translation of a thorough and extensive book published earlier (in Japanese), which will be of considerable interest to scientists worldng in the field, and to members of the general public interested in natura J ways of maintaining health. Both authors are themselves eminent researchers with extensive experience. Dr. Kuroda is best known for his publications employing tissue cultures. Dr. Ham has published nmnerous research papers on the health effects of green tea and its catechins. This book provides a comprehensive overview of the historical use of green tea in Japan and elsewhere, followed by a description of the many disease conditions against which these teas have preventive (protective) effects. Of particular interest to "senior citizens" is the chapter on the ability of tea components to ameliorate a wide range of age-related diseases including cancer, arteriosclerosis, and various forms of senile dementias. For scientists and others interested in infectious diseases caused by bacteria and viruses, a chapter dealing with the ability of tea components to inhibit these organisms will be of special interest.