Abstract-Innovation is required in mathematics teaching in order to improve students' mathematics literacy. This means that students learn mathematics with the emphasis of common sense and application of knowledge in their daily life. Innovation can be conducted by employing the Mathematics Education (RME) approach. This is a developmental research which followed reference [1] model to measure the quality of learning using RME approach. The developed learning materials consisted of lesson plan, student's worksheet, observation sheet, achievement test, students' response, validation sheet, and video lessons. The quality criteria of the learning materials refer to validity, practicality, and effectiveness. This paper only discusses the effectiveness of innovation in terms of teachers' concern. The people who are impacted by the innovation may react differently. Ten primary school teachers were involved in the implementation of RME. They completed the questionnaire of teachers' concern after the implementation of RME in their own class. The results revealed that teacher are highly concern of the implementation of RME to develop students' character. Teachers are willing to review more of the approach including the change they should do related to the implementation of RME. Teachers are not concerned of the time constraint and more responsibility.