Abstrak: Tujuan penelitian pengembangan ini adalah dihasilkannya perangkat pembelajaran matematika realistik di SMP yang telah tervalidasikan. Metode penelitian dilakukan lewat pengembangan model 4-D (four D model). Subjek uji coba terbatas perangkat pembelajaran adalah siswa kelas VII SMPN 2 Sukoharjo tahun pelajaran 2012/2013. Hasil penelitian berupa produk perangkat pembelajaran pada materi Aljabar di kelas VII SMP. Buku tersebut telah divalidasikan secara teoretis yang dilakukan oleh ahli di bidangnya; rencana pelaksanaan pembelajaran tertentu telah diuji secara terbatas keterbacaan dan disimulasikan;dan perangkat pembelajaran dan instrumen penelitian telah diuji coba terbatas. Kata Kunci: perangkat pembelajaran, matematika realistik DEVELOPING REALISTIC MATHEMATICS INSTRUCTION KITS IN JUNIOR HIGH SCHOOLS Abstract: This study was aimed to develop validated realistic mathematics instruction kits in junior high schools. The study was carried out using the four-D model. The subjects for the limited try out were the seventh grade students of SMPN 2 Sukoharjo in the academic year of 2012/2013. The product of the study was in the form of instruction kits of Algebra materials for the seventh grade students. The book had been validated theoretically by an expert; the lesson plan had been tried out and simulated; the instruction kits and the research instrument had been tried out. Keyword: instruction kits, realistic mathematics