This research was motivated by the students’ low learning outcome. It aimed to improve their learning outcome through discovery learning models assisted by manipulative media. This was a Classroom Action Research (CAR) and was conducted in 2 (two) cycles. Each cycle consisted of three meetings with one lesson plan for each. The research stages consisted of planning, action, observation and reflection. The subjects of this study were the fourth grade students of SD Negeri 1 Kradenan (Public Elementary School 1 of Kradenan), amounting to 26 students consisting of 11 males and 15 females. For its data collection tool, the researcher used observation sheets of teachers’ and students' activities. Data collection of affective and psychomotor learning outcomes were obtained using assessment sheets of both affective and psychomotor aspects. Data collection of cognitive learning outcome was obtained from evaluation result in the end of meeting. The occurring increase results can be viewed in each cycle. The research results indicated that the implementation of discovery learning models assisted by manipulative media can improve students' learning outcome of mathematics subjects on the topic of circumference and area of two dimentional figure in grade IV of SDN 1 Kradenan, Sumpiuh, Banyumas.