The study aims to know the role of logarithm learning design to introducing logarithm concept and the result at logarithm learning process through student worksheet based on Realistic Mathematics Education approach. The research method used is design research which was implemented in one of the Senior High School in Yogyakarta. The instruments used are test, video, and fieldnote. The result shows that the students look likes still adapt to learning design that implemented in the 1st and 2nd meeting, but in the next meeting the students can already start to follow learning process. Furthermore, the students result study show that the students' average value is 77.5 with frequency of completeness 65.6%.
Keywords: Design Research, Logarithm Learning Designing, Realistic Mathematics Education