Correct comprehension of the scientific terms is the bottom of understanding the general concepts contained is them. Therefore a study is required to analyze whether the students correctly understand the scientific terms. The associative method was used to evaluate the comprehensibility of the terms. The scientific terms in this study are selected in the textbook of science in the junior high school were selected. The frequency of the same associative word responsed and the frequency of no response from the selected students for given scientific terms were measured for 9 different groups. The terms which are not used in the daily life, especially for the terms with chinese character or abstract terms turn out to be difficult for the students to understand. It is purposed that the instructor should remember the importance of understanding the scientific term and carefully explain them to the science class.