Students' mathematical representation ability and interest in learning mathematics are still low. The purpose of this study is to determine the effectiveness of  the Guided Discovery learning model through a contextual approach to students' mathematical representation abilities and mathematical learning interests. The research method uses an experimental type of research. The populsion in this study is the entire class VIII MTs Al Ma'arif. The selected samples were class VIII A and class VIII D. Data collection techniques by providing mathematical representation ability test questions, and mathematical learning interest questionnaires. The results of data analysis show that the Guided discovery learning model through a contextual approach is effective for students' mathematical representation abilities and mathematical learning interests.