One of causes of low ability indonesian student’s is rarely trained in solving the problem’s. The development research is needed to provide insight and expand the literatures. This study aims at describing the processes and the results of development of Open-Ended learning materials on cuboid and cube. The development used the Plomp’s model. This model have 3 phases, preliminary research, development, and assesment. The results of the development materials Instruction is the form of Lesson Plan , Student Worksheet, Achievement Test, and Test Creativity. After has valid from validator, the learning materials were trialed at 20 junior high school students 8^th grade. Data were collected through sheet observation, achievement test, test of creativity, and questionnare. Another interesty results showed the instructions materials is good because meet criteria valid, practice, and effective. Further, it is expected to teacher use this material instrument.