Abstract: In this paper, visualization technology is introduced to optimization computing process for antenna structures. To overcome the difficulty that the Cartesian coordinate system cannot describe the multidimensional data space, a new powerful visualization tool, namely parallel coordinates visualization technology, is apphed to display interrelated information of design space, such as the information of gradient and restriction function. Then, optimization computing process is made transparent and visible. Thus, the optimization process can be tracked and manipulated and the efficiency and quality of optimization are enhanced to a certain extent.