本研究主要的目的是了解目前花蓮市青少年體能活動行為階段之情形，以及了解青少年在不同性別、種族、年齡的體能活動行為決定因素之差異。本研究針對花蓮市13-18歲青少年為主要樣本，隨機抽樣將作為本研究取樣之方法。研究者總共發放600份問卷給花蓮市13-18歲青少年填寫，問卷實際回收為578份，其中包括男性學生277位和女性學生301位，回收率為96%。本研究採用下列兩種量表：(1)體能活動自我報告和(2)體能活動行為決定因素量表，並且採用下列統計方法：因素分析、描述統計、t考驗、單因子變異數分析進行研究分析。研究結果發現：(1)不同性別在自信心、朋友支持、自我激勵、自覺能力上有顯著差異，男性學生在參與體能活動時較明顯受到自信心、朋友支持、自我激勵、自覺能力的影響；(2)不同種族在自我激勵上有顯著差異，原住民學生的自我激勵比一般學生高；(3)不同年齡青少年在體能活動行為因素上有顯著差異，花蓮市13-14歲的青少年較踴躍參與體能活動較15-16歲和17-18歲的青少年受到明顯的影響。經由研究結果進行以下之建議：(1)體育教學者可依據青少年不同背景變項提供多元性的介入教學策略，以提昇青少年實際參與體能活動的意願。(2)性別差異會影響體能活動的決定因素，加強宣導運動益處，協助提升運動自覺能力。(3)本研究樣本僅限於花蓮市，在推論上有所限制，未來研究者可比較花蓮縣城鄉青少年體能活動及其影響因素之差異。

Recently, many researches focus on physical activity and health areas. Once teenagers get used to inactive lifestyle, they will continue active lifestyle into their adulthood. (Marcus, Pinto, Simkin, Ahdrain, & Taylor, 1994; Sallis, Buono, Roby, Micale, & Nelson, 1993). The main purpose of this study was to understand the differences on students' determinants of physical activity between gender, races and age in Hualein County. The two questionnaires were utilized to collect data: (1) Self-Report for Physical Activity and (2) The Determinants of Physical Activity Questionnaire. The participants of this study were emphasized on 13-18 years old adolescence in Hualien County. Random sampling was utilized for this study. The researcher received 578 returned questionnaires, included 277 male students and 301 female students. 96% were returned validly. The study was utilized several statistical methods as following: factor analysis, descriptive analysis, t-test & One-way ANOVA. The results as following: (1) There were significant differences in determinants of physical activity (self-confidence, friend support, self motivation and perceived competence) between gender. Male students had higher scored than female students. (2) Aboriginal students had high scored in self motivation than regular students. (3) 13-14 year-old students were found higher participation in physical activity than the other two age groups.