This study was performed to develop a scale for evaluation of student athletes in sports groups and to examine its reliability and validity, focusing on verification of the sports self-management skills of individual athletes.   First, 61 items were developed using existing scales. These items were then administered to 126 student athletes (5 teams, 66% male) using a 5-point rating scale and an open-ended questionnaire. To ensure objectivity, a university teacher from a department other than sport, 5 university teachers specializing in sport, and 3 graduate students from the same field also examined the items collected and developed. The items were examined for whether they expressed “self-management skills.”   In the main research, an exploratory factor analysis was conducted using data from 603 student athletes (35 teams, 51% male) from various athletic clubs in Kanto, Japan. This revealed that 32 items were divisible into 8 factors: team contribution, thinking ability, self-introspection, conscientious attitude, continuous effort, achievement effort, task improvement, and creativity and originality.   By analyzing these factors, sufficient reliabilities were confirmed: the Cronbach's alpha coefficient was .66-.83 on the scale. The construct validity was supported because significant correlations with the existing scales were evident.   Comparison of the score between the team's affiliation level and the 8 factors of sport self-management skills revealed that for 7 of the factors, with the exception of “conscientious attitude”, the score for self-management skills of a high-level sports team became higher than the others. Thus, with regard to verification of validity, it was revealed that a team composed of individuals with high sport self-management skills also played a high-level game.   Thus, the final sport self-management skill scale comprised 4 items for each of the 8 factors, adding up to 32 items.