The purpose of this study was to make a check-list by which psychological-competitive ability of athletes can be diagnosed. A questionnaire was administered to male and female athletes. The results obtained are summarized as follows
　1. Factor analysis was applied and five factors were named as follows ; ability to increase a competitive motivation (include endurance, fighting spirit, self-actulization and intention to win), ability to stabilize and concentrate mental state (self-control, relax and con-centration), ability of confidence (confidence and determination), ability of strategy (anticipation and judgement) and cooperative ability.
　2. The relationships between the five factors and various traits of athletes were very remarkable. Accordingly, we guessed a possibility of predicting and diagnosing about psychological-competitive ability of atheletes by this quetionnaire (52 items).
　3. On the basis of these results, a short form of check-list (10 items) was maked in order to appreciate mental state of athletes in competition.

DESCENTE SPORTS SCIENCE Vol.12/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE