本研究係以重量守恆推理能力為主，探討學生對物質變化的錯誤概念， 主要的研究目的如下:1.分析學生的物質變化概念及其重量守恆的推理模式。2.探 討學生的物質變化概念和其變化時重量守恆的關係。3.探求學生的形式操作推理 能力和物質變化前後重量守恆的關係。本文所使用之工具係自編的一種診斷工 具，主要概念包括溶解、蒸發、昇華、燃燒、氧化、化學反應等;並採用示範實 驗群測的研究步驟。計有六所國中共775位的國中學生接受測試。主要發現如下; 一、關於物質變化可歸納成三種錯誤思考類型:1.錯誤的物質概念。2.不正確或不 適當的物質變化概念。3.物理變化與化學變化之混淆二、在重量守恆推理方面， 常見約正確推理方式有:1.應用物質變化過程的知識。2.可逆性、同一性及互補性 推理。3.使用定律或定則。三、不正確的重量守恆推理型態則為:1.缺乏物質變化 過程的知識。2.缺乏整體性的考量，僅考慮物質產生變化的部份。3.錯誤的物質 概念。4.受日常經驗的誤導四、物質變化前後的重量守恆的正確推理，與學生是 否瞭解物質的變化過程有顯著的相關，並且與是否具有排水體積守恆推理能力有 顯著的相關。

　　　　　This paper was to study students' conceptions and reasonings about the transformations ofmatter and conservation of weight. The main purposes for conducting the study were:1.to analyze how students perceive the transformations of matter and weight conservation when matter transformed.2.to investigate the relationship between students' conceptions about the tansformations of matter and weight conservation when substance transformed.3.to study the relationship between students' cognitive development and weight conservation abilities when matter transformed. The test instrument for measuring the students' conceptions is a form of group demonstrationtest, which was developed from the first author by referring to some of the other research results. The test consists several concepts : dissolution ' evaporation sublimation ' oxidation andchemical reaction. There were 775 students selected from six junior high schools as the subjectsfor the study. The results of this study were:1.Three types of students' misunderstandings about the transfromations of matter were found as follows:(l)lncorrect conceptions about matter, (2)lncorrect or improper conceptions about the matter transformations, (3)Confusion between chemical change and physical change.2.Four types of students' correct reasoning on weight conservation were found: (l)To posses conceptions about the transformations of matter, (2)Reversibility ' identity and compensation reasoning, (3)The weight is unchanged in closed system, (4)To use laws or rules, such as the low of mass conservation.3.Four types of students' incorrect reasoning of conservation of weight were also found: (l)To lack conceptions about the transformations of matter,(2)0nly consider part of the matter transformed and missing the whole situation, (3)lncorrect conceptions about matter. (4) To mislead by daily life experience.4.The more information students acquired about the transformations of matter, experically inmore complicated transformations, the easier it is for them to judge and reason correectly about the weight of matter when matter transformed.5.The students who were able to operate formaley can easily judge and correctly reason about the weight of matter when matter transormed.