本研究以健康促進模式為研究架構，目的在檢驗人際影響（社會支持、規範仿效）、特定行為認知（自我效能、知覺利益、知覺障礙）、和當時行為競爭的需求行為等各種變項與青少年身體活動的相關性。本研究採結構式問卷進行橫斷式研究，量表的內部一致性之Cronbach's α係數介於.83至91之間；以身體活動結果變項進行因素分析及關聯性考驗，結果顯示有良好的建構效度，因此，此研究所使用之問卷具有良好的信效度。以方便取樣選取臺北市某兩所國中二年級學生為樣本進行調查，有效問卷共 969 份。 將所得的資料，以自變項中的中數為基準，高於中數列為高組，低於或等於中數列低組，以 t 考驗檢驗高組和低組之身體活動與自變項的關係，研究結果經分析討論後，發現：（一）有較多正面人際影響的青少年，其身體活動量高於獲得較少正面人際影響者；（二）對身體活動有高自我效能、高知覺利益和低知覺障礙的青少年比具有相反的認知者，更可能參與身體活動；和（三）和當時行為競爭需求變項與青少年身體活動沒有顯著相關。本研究建議：（一）特定行為認知與同儕影響對青少年身體活動參與，扮演了重要的角色，在未來規劃健身運動促進或體育課程時，可作為介入的重要變項；（二）父母除對這些青少年設定期望外，也應該做為青少年的身體活動和積極生活的模範並提供適當的鼓勵及幫助。

　　　　　Based on the Health Promotion Model, the purpose of this study was to examine the relationships between interpersonal influences (i.e., social support, norms, modeling), behavior-specific cognitions (i.e., self-efficacy, perceived benefits/barriers), competing demands and physical activity among Taiwanese adolescents. The cross-section survey with structured questionnaire was employed in current study. Cronbach's alphas ranged from.83 to.91. Construct validity was supported by confirmatory factor analysis and correlation with the outcome variable of physical activity. The instrument used in this study has satisfactory internal consistency and validity. A convenience sample of 969 Taiwanese eighth graders from the Taipei School District completed a self-administered questionnaire. A median split was used to create two groups on independent variables: a group of cases with values larger than the overall median (high) and a group of cases less than or equal to the median (low). Differences in physical activity between the high/low groups were examined by t-tests. Finding were as follows: (a) Adolescents who have more positive interpersonal influences (i.e., support, norms and modeling) from parents and peers reported higher levels of physically active than those who have less positive interpersonal influences; (b) Adolescents with higher self-efficacy, higher perceived benefits, and lower perceived barriers toward physical activity reported more participation in physical activity than those with opposing cognitions; (c) The relationship of competing demands and physical activity of adolescents was not statistically significant. The current study also identifies factors such as behavior-specific cognitions and peer influences pertinent to participation in physical activity which can provide the focus of an intervention program. Taiwanese parents need to be encouraged to model physical activity and active lifestyles among youth in addition to setting expectations.