本研究旨在以結構方程模式驗證與分析「科學學習成效理論模式」，探討學生整體科學學習成效各潛在變項間交互影響之機制。研究樣本為572位國二學生，研究工具包括科學學習動機量表、科學概念學習測驗、科學推理課室測驗與科學學習成就測驗。結果顯示，理論模式大致符合適合度檢定標準，經分析潛在變項間之各項效果，學生整體科學學習成效之路徑包括：一、科學學習動機會直接影響科學概念學習、科學推理能力與科學學習成就；二、科學學習動機以科學推理能力與科學概念學習為中介間接影響科學學習成就；三、科學推理能力直接影響科學概念學習與科學學習成就，也透過科學概念學習間接影響科學學習成就。根據研究結果，本研究對科學教學與未來研究提出建議。

This study is to examine and analyze the Theoretical Model of Scientific Learning Effectiveness by Structural Equation Modeling. We investigated the relationships of the latent variables in the whole students’ scientific learning effectiveness and chose the samples are 572 eight-grade students from six junior-high schools in Taiwan. The instruments included Scale of Scientific Learning Motivation, Classroom Test of Scientific Reasoning, Test of Scientific Conceptions Learning and Test of Scientific Learning Achievement. The results of this study show that theoretical model match model fit criteria with the observational data. Analyzing standardized effects, the main findings included: (1) the students who held more positive scientific learning motivation they will have better scientific reasoning ability, scientific conceptions learning and scientific learning achievement; (2) scientific learning motivation on scientific learning achievement indirectly by mediating scientific reasoning ability and scientific conceptions learning; (3) scientific reasoning ability not only influences scientific conceptions learning and scientific learning achievement directly, but also influences scientific learning achievement indirectly with mediating scientific conceptions learning. According to the results of this study, some suggestions for science teaching and future research were discussed.