To know the directional efficiency of cursor moving is important for the purpose of guiding the rearrangement of icons and toolbars in the window environment. This rearrangement resolution can achieve better computer access especially in the clients with quadriplegia. However, the information about the directional efficiency of cursor movement is not clear even in the typical persons. Therefore, before surveying the quadriplegics, typical persons were researched in this study. Four typical persons simulated quadriplegics to operate trackball with their right dorsal hand and the kinematic parameters of cursor moving were measured. The single subject experimental research (SSER) with alternating treatments design was used to compare the effects of four cursor moving direction (right to left, down to up, left to right, and up to down) on the kinematic variables. The prior auto-correlation coefficients and Bartlett's ratio values were computed to make sure there was no any series dependence between measuring points before conducting parametric one-way repeated measures ANOVAs. From analyzing the parameter of deviation from the straight line, velocity, movement unit and execution time, the efficiency to move on the horizontal direction (left to right or right to left) was better than move on the vertical direction (up to down or down to up). To further know the cursor kinematic performances in patients with quadriplegics will be important.