Tai Chi as one of health exercises is becoming more and more popular in the world. Many studies show the evidence Tai Chi can improve balance, prevent fall. As an example of its health benefits, Tai Chi is an effective treatment for knee osteoarthritis in older adults showed by many studies. In addition, Tai Chi exercise can lead to significant reduction of knee pain. Despite many positive reports, some reports caution that Tai Chi may also cause practitioners' knee pain; even some practitioners cease to practice due to Tai Chi induced knee pain. We have surveyed 1000 Tai Chi practitioners in the greater Shanghai metropolitan area. Our results detailed the demographics of Tai Chi practitioners in the area. We also will present an analysis of multiple knee health related questions. In addition, the relation of knee joint health and Tai Chi practice were investigated. One of our results showed that approximately 50% Tai chi practitioners reported they had knee pain before they have started Tai chi practice. Most Tai chi practitioners who have knee pain symptom agree that Tai chi exercise can effective reduce knee pain. This result is consistent with former studies. Based on the literature and our data, Tai Chi practice with proper caution can increase knee joint health, prevent degenerative knee joint disease and improve practitioners' quality of life.Keyword(s): health promotion, interdisciplinary, research