eng Science and Education Publishing American Journal of Educational Research 2327-6150 2018-10-28 6 10 1397 1402 10.12691/education-6-10-9 EDUCATION20186109 article Aman Sanusi Siregar sanusisiregar7@gmail.com 1 Edy Surya 1 Edi Syahputra 1 Asril Rais Sirait 1 Graduate Program School in Mathematics Education, State University of Medan, Indonesia This purpose of this research to know: (1) The improving of mathematical communication ability and students' self regulated learning through realistic mathematics approach based on Batak Toba culture is higher than students who are given regular learning, (2) there is interaction between learning approach with initial ability of mathematic (KAM) in improvement of students mathematical communication ability and students' self regulated learning. This research type is quasi experiment. This research was conducted at SMP N 2 Dolok Panribuan. The population in this study is all students of class VII. Based on the results of the analysis, the research results are obtained: (1) improving of mathematical communication ability and students' self regulated learning through realistic mathematics approach based on Batak Toba culture is higher than students who are given regular learning, (2) there is no interaction between learning approach with initial ability of mathematic (KAM) in improvement of students mathematical communication ability and students' self regulated learning. Recommended by the teachers can use realistic mathematics approach based Batak Toba culture by presenting issues related to local culture as an alternative learning. http://pubs.sciepub.com/education/6/10/9/education-6-10-9.pdf mathematical communication ability self regulated learning realistic mathematical approach based on batak toba culture