Through analyzing the reconstructed optical distribution in the displaying stage, the relationship among micro-lens parameters, planar recording resolution and spatial resolution of the integral imaging system is obtained. The results show that the spatial resolution is relevant to the pitch size and focal length of the micro-lens. Small sized micro-lens is preferred to improve spatial resolution. However, the requirement for planar recording resolution increases with the decrease of the micro-lens size. The requirement for recording resolution also increases with the increase of the object depth. The results can be used in the optimal design of integral imaging.