本研究之目的，主要係透過一位任教國小六年級自然科的李老師教學信念及教學實務，來瞭解以科學本質為基礎的課程設計及教學成效。本研究運用教室觀察、訪談、凱利方格技術、文件分析等方式，配合問卷調查蒐集資料，藉多元資料描述教師的科學本質觀及以科學本質為基礎的教學實務。研究結果說明了李老師的科學本質觀較傾向於當代的科學本質觀，在科學方法本質向度上，認為科學研究始於問題的產生、研究方法具多元性、探究重視假設的形成、解決問題及減少誤差，而對科學知識的本質上，認為具實證性、暫時性、可複製性及公開性，最後在科學事業本質向度上，強調科學與生活相關，同時重視群體的合作與討論，李老師亦試圖將此理念應用在其教學方案中，並實踐之。根據發現與結果，本研究對於課程與教學、教育行政等分別提出建議，可作為科學教育研究與教學實務的參考。

　　　　　The purpose of this study, mainly through an elementary science teacher's (Mrs. Lee) conceptions and practical teaching, explored the effectiveness of the self-designed curriculum based on the nature of science. Techniques such as classroom observations, interviews, Kelly's repertoire grid, and document analysis, were widely applied in this study, as well as the questionnaires needed for collecting more data. Results showed that the Mrs. Lee's conceptions of the nature of science inclined to constructivist's perspective. Firstly, regarding to the dimension of the nature of science methods, she indicated that (1) the beginning of science research was initiated from raising questions, (2) multi-ways to solve problems, (3) emphasis on hypothesis formulation, (4) decreasing the errors from each experiment. Secondly, as the nature of science knowledge, she described it as experimental, temporary, replicable, and as becoming public knowledge. Thirdly, for the dimension of the nature of science enterprise, she believed that there was close relationship between science and life, and focused on the cooperative discussion among community. Mrs. Lee put all three conceptions into the science planning and classroom instruction. The study also provides the conclusions and suggestions for curriculum and instruction, educational administration and further research, and also functions as a valuable reference for the study on science education reform.