A general expression of discretional target position with its correlation peaks in correlation output is proposed based on the theory of joint transform correlation (JTC), and the single and multiple targets correlation experiments are also simulated. The characteristic of correlation peaks variation of moving targets is analyzed. The results show that dissymmetrical correlation peaks are always symmetric at two sides of coordinate centre, and the connections of correlation peaks with coordinate centre are parallel with the input target center with reference target centre. The distance of correlation peaks with coordinate center equals the input target with reference target. In addition, the correlation peaks change with the targets moving, and the value of coordinate changes are also equal.