近年來，大型資料庫的建制與分析逐漸成為一種教育研究趨勢，本研究即以PISA 2003資料庫為例，目的是建立影響數學成就的結構方程式模型。在評閱相關文獻後，研究者採用內在動機、工具性動機、數學焦慮、自我概念與數學成就等變項，探討之間的影響關係模型。此外，為使本研究所建立的模型具有模型穩定之證據，因此，將有效樣本隨機分割為建模樣本與驗證樣本，進行最終模型的交叉驗證。 據此，本研究首先使用描述性統計以瞭解香港學生的整體表現傾向，其次，透過探索性因素分析確立研究問卷的信效度，最後，以結構方程式模型建立模型並交叉驗證。資料蒐集對象為香港十五歲之在學學生，有效樣本達4,389位。 依據統計分析結果顯示，內在動機與工具性動機對數學成就沒有直接影響效果，但是內在動機與工具性動機透過數學焦慮及自我概念對數學成就產生間接影響，本研究歸納出七點結論茲分述如下： 1.工具性動機較內在動機更為強烈 2.數學焦慮在動機與數學成就間扮演中介變項之性質 3.自我概念在動機與數學成就間扮演中介角色 4.自我概念在數學焦慮與數學成就間扮演中介角色 5.在內在動機、工具性動機與數學焦慮中，工具性動機扮演負向壓抑變項角色 6.在內在動機、工具性動機與自我概念中，工具性動機扮演負向壓抑變項角色 最後，根據研究結果提出各項建議，以供教學實務上及未來研究參考。 / Recently, establishing and analyzing databases becomes a trend in the field of education research. This study took PISA 2003 database as an example to create a psychometric model of factors that influence mathematics achievement. Based on the literature review, the researcher decided to put influential factors, including intrinsic motivation, instrumental motivation, mathematics anxiety, self-concept, and mathematics achievement into the model. Afterwards, through cross-validation the present study had verified the model stability. In the aspect of statistic analysis, the descriptive static shows HK students’ general learning tendency. Moreover, the exploratory factor analysis confirmed the reliability and validity of the questionnaires. Lastly, the structural equation modeling(SEM) was used to set structural model. The valid samples were 4,389 15-year-old students. According to the results, intrinsic motivation and instrumental motivation had no direct effect on mathematics achievement and had indirect effect through mathematics anxiety and self-concept. The results were summarized as follows: 1.Students had more instrumental motivation than intrinsic one. 2.Mathematics anxiety was a mediator variable between motivations and mathematics achievement. 3.Self-concept was a mediator variable between intrinsic motivations and mathematics achievement. 4.Self-concept was a mediator variable between mathematics anxiety and mathematics achievement. 5.Instrumental motivation was a negative suppressor variable among intrinsic motivation, instrumental motivation, and mathematics anxiety. 6.Instrumental motivation was a negative suppressor variable among intrinsic motivation, instrumental motivation, and self-concept. Finally, according to the findings, implications and suggestions for teaching of mathematics and future research were discussed.