The purpose of this study was to clarify the factorical structure of attributional styles in sport situations, and to examine the effects of sex, developmental level, sport experience, and attitude toward sport on attributional styles by comparing with factor scores. A questionnaire designed to measure attributional styles in sport situations was developed and administered to 232 subjects. Principal factor analysis with normal vafimax rotation was applied to the two correlation matrices (positive and negative situations) and then the factor scores were compared. The main results were as follows: 1) In positive situations, 6 factors (interpreted as ability, teacher, effort, luck, difficulty, and opponent) were extracted, and, in negative situations, 6 factors were interpreted as ability, teacher, effort, luck, opponent, and difficulty. 2) It was inferred that in one hand males attributed the positive events to ability, difficulty, and opponent, and the negative events to difficulty, but on the other hand, females attributed the positive and negative events to effort. 3) It was inferred that, in accordance with the advance in age, effort attribution decreased, while ability and opponent attribution increased. 4) It was inferred that the tendency to attribute the positive events to ability and effort, and the negative events to effort increased in accordance with the advance in sport experiences. 5) It was inferred that the subjects who showed unfavorable attitude toward sport tend to attribute the positive enents to luck, and the negative events to ability and effort. These results and their implications were discussed.