Balance ability is an important affecting factor for both sport technique and daily life. In general, men could improve their balance ability through regular exercise training, Tai Chi Chuan exercise is an obvious one. In exercising Tai Chi Chuan, keeping the body straight and being relaxation is emphasized, the center of gravity of the body always has a precise location. These rules would help the learners to improve their balance ability. The present study aimed at comparing the difference of balance ability to 60 undergraduate students before and after a 15 weeks Tai Chuan course was given. The outcomes are as follows: 1. To test the balance ability by standing on one foot at hard surface ground with eyes closed, the average time for standing on right foot increases 2.92 seconds, while standing on left foot increases 4.94 seconds, which reaches the obvious level (p<0.05). 2. To test the balance ability by standing on one foot at soft surface pad with eyes closed, the average time for standing on right foot increases 3.15 seconds, while standing on left foot increases 3.36 seconds, which also reaches the obvious level (p<0.05). The possible reasons for the above results be as follows: 1. Tai Chi Chuan exercise always keeping the body straight, relaxation, and paying attention to the move of body center of gravity. 2. Young's Tai Chi Chuan has a low profile, the students were doing single foot supporting and keeping the balance of body most of the time while exercising. 3. Tai Chi Chuan exercising also requires the coordination between movement and breathing, so that the body motion would get more stable and concord.