This research aimed to produce space learning kits with realistic mathematics education approach in Junior High School which valid, practical, and effective viewed from achievement of basic competence, mathematical connection ability, and mathematics interest. This research was development research used 4-D model that consisted of four phases: defining, designing, developing, and disseminating. This research produced space learning kit that consisted of syllabus, lesson plans, students' worksheets, and assessment tests that included test of basic competence achievement and mathematical connection test which valid, practical, and effective. The validity of learning kit get very good category from expert assessment. The practicallity of learning kit get very good category from teachers assessment, students assessment, and observation of learning implementation. The aspect of effectiveness was seen from achievement minimum 80% of the student pass the minimum score for achievement of basic competence and mathematical connection skill, and more than 80% of student have mathematics interest in least good category.