目的：本研究的目的是調查臺灣地區的兒童及青少年的運動參與動機，並檢驗性別和年級在參與動機和身體活動量的差異。方法：以問卷調查臺灣地區國小三年級到國中九年級（9~15歲），共3321位兒童及青少年。結果：一、描述性統計分析顯示不同性別或年級，最主要參與運動的理由是“健康”和“技能促進”。二、因素分析歸納出6個動機類別（解釋變異量49.73%），分別是「健身和技能促進」、「社會期望和外在因素」、「競爭和挑戰」、「社會增強」、「正向情緒和友誼」、「團隊合作」。三、MANOVA分析結果顯示顯著的性別主要效果(Wilks' Λ=.94, F(下標 (7, 3213))=31.33, p<.001)，在身體活動量和大部分的動機（除了團隊合作外）男生皆顯著的高於女生。另外，也發現有顯著的年級主要效果(Wilks' Λ=.78, F(下標 (42, 15106))=19.30, p<.001)，除了「正向情緒和友誼」之外，大致上隨著年齡發展在各類別的參與動機有逐漸下降的趨勢。在身體活動量的部分隨著年級增加至六年級是最高的，但六年級之後就急速下降，至九年級是最低的。結論：兒童及青少年知覺和健康有關的運動參與動機是最重要的，且參與動機和身體活動量會隨著性別和發展階段而改變。

Purpose: To survey the participation motives of children and adolescents in Taiwan and to examine the effects of gender and grade and the amount of physical activity. Methods: A total of 3,321 students, grade 3 to 9 (1,701 boys, 1,620 girls), from various regions of Taiwan were surveyed via questionnaires. Results: 1. Descriptive analyses showed that motives related to fitness and skill enhancement ranked the highest for all ages. 2. Factor analysis showed 6 categories of participation motives (49.73% total variance explained), namely, fitness and skill enhancement, social expectation, competition and challenge, social reinforcement, fun and friendship, and team interaction. 3. MANOVAs found a significant gender effect (Wilks' λ=.94, F(subscript (7, 3213))=31.33, p<.001). Boys scored higher than girls in the amount of physical activity and in most of the other participation motives (except team interaction). Grade was also found to have a significant effect. (Wilks' λ=.78, F(subscript (42, 15106))=19.30, p<.001). Fun and friendship increased as grade increased but scores of for the other motive categories decreased. The amount of physical activity increased as grade 1 increased to grade 6 but decreased thereafter and 9 graders had the least amount of activity. Conclusion: This study categorized the participation motives in physical activities of children and adolescents in Taiwan, and health related reasons were reported as the most important. However, participation motives and the amount of physical activity changed as a function of gender as well as the age of development.