Abstract The main purpose of this study is to investigate, through the ¡§Series¡¨ unit in the first volume of high school mathematics, the impact of the updated-version textbooks on the learning effectiveness of students so as to provide references to be used by future revisers of teaching materials. The research subjects were drawn from Kaohsiung City high schools. Three schools were selected (two public and one private). These three high schools, from the 1999 academic year, began to use mathematics textbooks of three different versions, one to each school. A first-year class and a second-year class were drawn from each school, and there were six classes in total. In total there were 237 students receiving the experimentation. The students from the same school, no matter they were first-year or second-year, had been taught by the same teacher in respect of the unit that was included in the study. Among the three schools, School ¥Ò®Õ admitted for the 1998 and 1999 school years new students with scores higher than 580 on the joint entrance examination, School ¤A®Õadmitted for the 1998 and 1999 school years new students with scores from 530 to 580 on the joint entrance examination, and School ¤þ®Õadmitted for the 1998 and 1999 school years new students with scores lower than 530 on the joint entrance examination. The three new versions used in the study were published by Nan-I Book Store, Ta Tung Information Enterprise, Co., Ltd., and Han Lin Publisher respectively. They are high school mathematics textbooks examined and approved by the Ministry of Education (excluding Teacher¡¦s Manual, supplementary materials, journals, reference books, etc). The outdated version was published by National Bureau of Editing and Translation. Mathematics Test written by the researcher was used as the testing tool, and the t-test method was adopted. Moreover, because the variances of the file data collected from a school fluctuated tremendously and the sample space was unequal, a single-factor ANOVA analysis was conducted to indicate whether there existed a significant difference between classes in terms of their learning achievement. The ¡§Questionnaire on Mathematics Opinions¡¨ was administered and the results were represented by ¡¥5¡¦, ¡¥4¡¦, ¡¥3¡¦, ¡¥2¡¦, ¡¥1¡¦, which indicated their scores. An ANOVA analysis was conducted to investigate the differences in students¡¦ learning attitude. After synthesizing the analytical results of this study, the author has come up with the following conclusions: ¤@¡BIt is known from t-test and ANOVA analysis: in School ¥Ò®Õ, there existed a significant difference between the first-year and the second-year students in respect of their learning effectiveness; in School ¤A®Õ, there existed no significant difference between the first-year and the second-year students in respect of their learning effectiveness; in School ¤þ®Õ, there existed no significant difference between the first-year and the second-year students in respect of their learning effectiveness. ¤G¡BAccording to the correct percentage of each question made by students and the error pattern, the test questions were classified into three types: concept, calculation, and comprehensive application (including questions that integrated comprehension, analysis, and application abilities). It was found from the classification of questions that: (1) Textbooks have no impact on both the well-established (School ¥Ò®Õ) and the weak (School ¤þ®Õ) students in respect of the effectiveness of learning concept questions. There is no difference between the outdated and the updated-version textbooks. However, as far as the students with ordinary achievement (School ¤A®Õ) are concerned, the updated-version textbooks have a significant impact on learning effectiveness. (2) Textbooks have an impact on both the well-established (School ¥Ò®Õ) and the weak (School¤þ®Õ) students in respect of the effectiveness of learning calculation questions, and the first-year students have benefited more from the updated-version textbooks than have their second-year counterparts in terms of the effectiveness in learning calculation questions. However, as far as the students with ordinary achievement (School ¤A®Õ) are concerned, the updated-version textbooks have a significant impact on the effectiveness of their learning to reduce cycle fractions, but have no significant impact on their learning other calculation questions. (3) Textbooks have an impact on the effectiveness of learning comprehensive application questions, as far as both the well-established (School¥Ò®Õ ) and the students with ordinary achievement (School¤A®Õ) are concerned. Moreover, the first-year students have benefited less from the updated-version textbooks than have their second-year counterparts in terms of the effectiveness in learning comprehensive application questions. However, as far as the weak students (School¤þ®Õ) are concerned, the updated-version textbooks have a significant impact on the effectiveness of their learning comprehensive application questions. In particular, the updated-version textbooks have an especially significant impact on the effectiveness in learning the comprehensive application questions of regression principle. ¤T¡BFrom investigating the difference between attitude toward and effectiveness in learning mathematics as far as different groups are concerned, it has been found: There existed a significant difference between learning attitude and learning effectiveness as far as the first-year and the second-year students of School ¥Ò®Õ are concerned. There existed no significant difference between learning attitude and learning effectiveness as far as the first-year students of School ¤A®Õare concerned. There existed a significant difference between learning attitude and learning effectiveness as far as the second-year students of School ¤þ®Õ are concerned. There existed no significant difference between learning attitude and learning effectiveness as far as the first-year and the second-year students of School ¤þ®Õ are concerned. ¥|¡BFrom the correlation between the learning attitude (consisting of five sub- categories: learning habit, learning process, learning desire, learning method, and test preparation) and the learning effectiveness of the first-year and second-year students of the three schools, it has been found: ¡]1¡^ As far as the correlations between their learning effectiveness and their learning desire and between their learning effectiveness and their learning method are concerned, there existed a significant difference between the first-year and the second-year students. Because both learning desire and learning method are related to textbooks, the updated-version textbooks had a significant impact on the learning effectiveness of the first-year students of School ¥Ò®Õ. ¡]2¡^ On the average, there existed a significant correlation between the learning effectiveness of the second-year students of School¥Ò®Õ , School ¤A®Õ, and School ¤þ®Õ and each of the five sub-categories of learning attitude (learning habit, learning process, learning desire, learning method, test preparation). Their performance on each sub-category of learning attitude is more or less related to textbooks. Therefore, there existed a significant correlation between the updated-version textbooks and each of the five sub-categories of learning attitude. ¡]1¡^ The correlation between learning effectiveness and learning method presented by the first-year students of School ¥Ò®Õ and School ¤þ®Õ (especially School ¥Ò®Õ) is more significant than that presented by their second-year counterparts. ¡]4¡^ The correlation between learning effectiveness and test preparation presented by the first-year students of School ¥Ò®Õ, School ¤A®Õand School ¤þ®Õ is more significant than that presented by their second-year counterparts.