Development coordination disorder (DCD) is a disorder of visual-motor integration in children, so the study on coordination of vision and motion is essential to understand the mechanism of DCD. The standardized assessments with certain visual-motor tasks are often used to detect impairments in eye-motion coordination, which is the most important component for diagnosis of DCD. However, these assessments emphasize on motor performance of children, while ignoring the detailed process of eye-motion coordination in performing these tasks. Therefore, it is a need to develop a proper digital visual-motor system to detect the eye movement and body motion simultaneously during these tasks, to study the mechanism of a typical eye-motion coordination. Currently, the eye-motion system is based on marker to detect the joints and gaze points for integration. This kind of system is very expensive and the markers may affect children's behavior in the task of DCD assessment. In this study, an integrated and markerless eye-motion system is developed to detect children's behavior in DCD assessment. In this system, a multi-Kinect system is used to monitor body motion and extract the skeletal joints. The gaze point is detected by a head-mount eye tracker and will be integrated into the system of body motion using image processing method. With the proposed system, the skeletal joints and gaze points can be obtained simultaneously for further digital DCD assessment.