The purpose of this study examined the variation of physiological functions and fttness in the highest level of badminton athletes after one year training in order to provide the necessary information for the coaches, providing the scientific evidence for exercise prescriptions and training plans, and also contributing to promote the effectiveness of training in the highest level of badminton athletes in Vietnam. 12 male and 14 female badminton athletes were selected to examine the selection of indexes on two factors: physiological functions and fitness. The results showed that the variation of physiological functions and fitness level badminton player after one year training are growth. In measuring physiological function Wo/o = 5.02 percent (male), Wo/o = 8.79 percent (female) and fitness W percent = 6.2 percent (male), Wo/o = 5.45 percent (female).