Abstract. The Application of Research Based Learning Model in Upgrading of Natural Science Learning about a Force for 5th Grade Students of 1 Sikayu Elementary School in Acedemic Year 2013/2014. The purpose of this research is to describe the steps of Research Based Learning Model, to describ the upgrading of natural science learning about a force for 5th grade student , and to describe the constrains and solutions. This research is class action research. The research was conducted in three cycles every cycles is consist of planning, action, observation , and reflection. The subjects of this research were 28 studenst of Elementary School 5th grade the students 1 Sikayu who were 14 males and 14 females. The results of this research showed that the application of Research Based Learning Model was done excat of the step could upgraded of natural science learning about a force for 5th grade students.Keywords : research based learning, learning, natural scienceAbstrak. Penerapan Model Research Based Learning Dalam Peningkatan Pembelajaran IPA Tentang Gaya Pada Siswa Kelas V SDN I Sikayu Tahun 2013/2014. Tujuan penelitian ini adalah untuk mendeskripsikan langkah-langkah penerapan model Research Based Learning, mendeskripsikan peningkatan pembelajaran IPA tentang gaya pada siswa kelas V SD Negeri 1 Sikayu, dan mendeskripsikan kendala dan solusinya. Penelitian ini merupakan penelitian tindakan kelas. Penelitian dilaksanakan dalam tiga siklus dengan tiap siklus terdiri dari perencanaan, tindakan, observasi, dan refleksi. Subjek penelitian ini adalah siswa kelas V SD Negeri 1 Sikayu yang berjumlah 28 siswa terdiri dari 14 siswa laki-laki dan 14 siswa perempuan. Hasil penelitian ini menunjukkan bahwa penerapan model Research Based Learning yang dilaksanakan sesuai langkah yang tepat dapat meningkatkan pembelajaran IPA tentang gaya pada siswa kelas V SD. Kata kunci: research based learning, pembelajaran , IPA