Tai Chi (Ji) Quan, typically shortened to just “Tai Chi,” is a Chinese body-mind exercise. “Tai Chi” represents the Chinese Tao (Yin/Yang balance) philosophy and is paired with “Quan,” meaning fist or Chinese boxing. Thus, Tai Chi's roots are originally from a unique martial arts, whose movements are based on Tao philosophy. In fact, all its movements and applications are a reflection of Tao philosophy. There are several theories about when and by whom Tai Chi was developed, the most of popular one is that the Taoist San-feng Zhang in the Northern Song Dynasty (960-1126 A.D.) created it. The use of Tai Chi as an exercise for health promotion and disease prevention, however, did not start until it was modified and introduced by Lu-Chan Yang, a Tai Chi master, in the early 1800s. The Chinese government made significant efforts in 1956 to simplify Tai Chi so that people with different health conditions could all practice it. Tai Chi was introduced in the U.S. in the late 1960s and 1970s, but did not grab the public's attention until the publication of a study by Dr. Steven L. Wolf of Emory University School of Medicine in 1996, in which older adults taking part in a 15-wk Tai Chi program reduced their risk of falling by 47.5%. Since then, Tai Chi has been proved to have beneficial effects with respect to balance, reduced falls, and non-vertebral fractures, and beneficial as well to those with many other chronic diseases. Yet, most of the published studies, including many completed in China, only focused on the relationship of practice and health outcomes and few focused on the mechanism of the Tai Chi practice. While hypothesized in China for a long time that the benefits come mainly from the improvement of Qi/vital energy circulation, little scientific evidence supports the claim. This presentation will provide a broad view on what Tai Chi is through its history, styles, daily applications, and its contribution to health, wellness and harmony. Research challenges in Tai Chi will be outlined and addressed. Some recommendations on future developments of Tai Chi will be described and a recommendation for optimal Tai Chi practice will be provided. Keyword(s): research