This paper presents an augmented-reality based interaction gear game which is designed to be used as a learning material of Science and Technology course for elementary school students. With this game, the authors hope to increase concentration, interest, and efficiency of learning in class. Basically, through obtaining the coordinates of human skeleton with Kinect sensor, we are able to identify the user's physical movements and postures and design scenarios in the game; the virtual picture is shown in the image, and therefore, the user can interact with the picture in an audio-visual scenario. This game makes learning through interacting possible. It provides a learning course that educates and entertains. In addition, it helps students to learn the scientific concept of gear during the interaction.