In the treatise of the Compensation Theory of Unbalance Structure of Athlete's Performance Ability, the "some range" show restricts conditions in the usage. By founding two types of "cask model" on border condition, considering what structure is the unbalanced structure and how compensation is the unbalanced structure compensation is the two sides of the "some range". The new concept of compensation index can take the affection on quantify unbalanced structure and compensation. The establishment of individual model in favor of carries out respectively training. Compensation index can get up the affection of judge the athletic ability type, illuminate the complementary relationships and weather the athletic ability development lie in unbalance state.