摘要物質的粒子性質是學習化學時很重要的基本概念，本研究設計了診斷學生物質狀態概念的評量工具，希望能歸納出學生的思考模式與錯誤概念，再藉由自行設計的粒子模型模擬三態變化的教具進行教學，嘗試導正學生的錯誤概念。研究對象為國中一至三年級學生，共計623人，研究目的為：(1)分析國中學生對於「物質狀態」之思考模式。(2)探討國中學生對於「物質狀態變化」概念的瞭解。(3)應用粒子模型之模擬教具的教學對學生學習物質狀態概念的影響。研究結果發現：一、 日常生活中常有學生將水沸騰後凝結而產生的水珠稱為「水蒸氣」，因此造成許多國中生以為水蒸氣是液體的錯誤概念，同時亦會影響學生判斷其他物質狀態時的想法。二、 國中生以粒子概念來描述氣體組成的所佔的比例最低，其次為固體，佔比例最高的是液體組成；國中生對於物質微觀組成概念的答對率，有隨著年級之增加而增加的趨勢。三、 密閉容器內物體發生狀態變化時，國中生在物體「質量」與「體積」二者變化情形的想法上有明顯的相關性。四、 使用粒子模型之模擬教具以進行教學，對於國中學生的物質狀態概念的改變是有助益的，此種教學方法尤其對學生在固體狀態時之微觀組成有明顯的進步。 Abstract The particulate theory of matter is a fundamental concept that is important in the process of learning chemistry. This study was designed to determine how well the students understand the concept of the states of matter, and to discover students’ thinking models and their misconceptions. Through the designed a kit of particle model, the simulated state change of matter can be used for the promotion of students’ concept understanding. The subjects of this study were 623 junior high school students. The purposes for the investigation of students’ understandings were as follows. (1) the analysis of junior high school students’ thinking models on “states of matter”; (2) the degree of student’s understandings towards “the changes of the states of matter”; and (3) the influences of using particle model as a stimulated kit in students’ learning process on the states of matter. The results were as follows: 1. Students often referred to the droplets which condensed from the steam after the water was boiled as “vapor”, therefore it formed a misconception to many junior high school students, they treated vapor as liquid. This influenced students’ understandings on the states of matter. 2. The proportion of students who could use particle concept to describe the formation of gas was the lowest, while the proportion of liquid was the highest, and that for solid was in the middle. The degree of students’ understandings on the formation of matter was increased progressively with their grade growth. 3. When a substance state was changed in a closed container, junior high school students thought that the changes of “mass” and “volume” exist obviously some relationship. 4. By applying particle model as a simulated kit, it could help junior high school students to improve their understanding the concept of the states of matter. Students had significantly improved especially on the formation of solids.