"Problem-posing" is an experience-converting instructional strategy for effectively enhancing students' thinking abilities and is broadly discussed in many domains. This study aims to probe into the possibility of technology assistance for problem-posing strategy. Based on the design principles of problem-posing and game theories, we designed a game-based problem-posing and solving system. Moreover, the influences of game-based problem-posing Math learning activities for students' problem-posing, problem-solving abilities, and flow are discussed. Four classes of fifth graders were participated in the research. Two classes were provided with game-based problem-posing system, while the other two used paper-based problem-posing method. The result shows that game-based problem-posing system positively enhances students' overall flow and problem-posing abilities.