Mathematics have sub chapter about geometry. Flat shape is part of geometry learned in elementary school. Flat shape is a two dimensional flat-which has no space but only a field. In general mathematics learning method about flat shape, the teacher just gave information, describing the example form up on the Board, and students follow the example of an image that is exemplified by the teacher to drawn on the book students. However, the results obtained by students are still far from expected. As for the purpose of this research include description of teacher's activity, student's activity, and student learning outcomes in mathematics learning about flat shape by applying a media concreteobjects on the grade II. The methods used in research is quantitative descriptive research methods. Implementation procedures of the research that was used to follow the basic principles of class act consisting of planning, implementation, observation, and reflection. Then the data were analyzed according to indicators of success. From the research that has been done, the results of the analysis of the data showed that by using media concrete objects, obtained a teaching success with achievementof all the indicator'ssuccess, so teachers need to apply these methods to improve the learning results of students on the material flat shape.