The purpose of the research is to improve problem solving skill of plane geometry of the student in Grade V of State Primary School Mangkubumen Kulon No. 83 of Surakarta in academic year of 2017/2018 by implementation of the AIR’s steps (Auditory, Intellectually and Repetiton) learning model bases Flashcard. The form of this research is Classroom Action Research (CAR) which the implementation with three cycles. Each cycle consists of four steps, there are planning, acting, observing, and reflecting. The subjects of this research are the teacher and the students as many as 24 students of the student in Grade V of State Primary School Mangkubumen Kulon No. 83 of Surakarta in academic year of 2017/2018. The data collecting techniques are observation, interview, test, and content analysis. Data validity tests are using content validity and triangulation. The data are analysis by interactive analysis model.The results shows that the classical completeness has increase, from 20.83% in pretest, 38.1% on cycle I, 87.5% on cycle II, and then 91.67% on cycle III. However, 8,33% (2 students) still earned the score ≤ 70 due to their constraint in Mathematic especially in numeracy skill. As a follow up, they are give more guidance and remedial test by the teacher. The result of the assessment of study activity and teacher performance appraisal also increase.Thus, the application of AIR learning model bases Flashcard can improve the problem solving skill of the student in Grade V of State Primary School Mangkubumen Kulon No. 83 of Surakarta in academic year of 2017/2018.