The problems of ego and self have been investigated in the circles of clinical and personality pychologists for a years but new trends of the development of modern sport express quite intensive need to reinvestigate those problems and factors on the area of sport. Fast development of top sport, higher and higher achivements and searching for new limits in sport contributed to the development of specific sport identity. These are the main reasons why the need for complex researching of factors and development od sport identitty exists. The relation between sport identity and top performance goes to both sides. Higher sport identity contributes to better motivation and more stable personal structure, which together contribute to better results and performance. And again better results contributes to higher expressed sport identity. High expressed sport identity at athlete is crucial in top sport for its contribution to more stable and long lasting top results in sport. With the project we will try to investigate intrinsic (personality) and extrinsic (social) factors of the development of sport identity and research their relationship with the level of top result in sport. 300 categorized adult male and female athletes will be questioned with the psychodiagnostics inventories for researching personality, motivation, values, SES, health and other external characteristics (training conditions, material state). Those findings will help us to make suggestions how to establish and build an effective surrounding support to the athletes which would help them to reach more sistematically and long lasting top results. This is of great importance because such top results are very important not only to certain athlete but also to the group and national identity. The applicative value of the project lies in suggestions how to build the best possible internal and external support to the development of an athlete's sport identity.