The purpose of this study is to review, through case study, how the use of web materials has influence on the improvement of self-oriented Learning in mathematics of primary school. This is one of the ways to improve classroom lectures suggested in the 7th National Standard of Curriculum. To accomplish this, the following three studies were conducted. First, a questionnaire concerning the improvement of self-oriented Learning Skill through the use of the materials on the web was designed and analyzed. Second, the activities of the class using the web materials were recorded and the study activities of the children were observed. Third, the process of writing notes about their study using web materials was analyzed though interviews after teaching and learning. Through these studies, it has been shown how web materials contribute to the improvement of self-oriented Learning Skill.