The operation speed of modern embed system has been upgraded from several hundred MHz to GHz. The signal vias through power/ground plane can have strong coupling effect and result in signal integrity problem. Analytical model including calculation of resonant frequencies, fields for simple rectangular structures can be used to estimate the resonant frequency and ideal position to place signal vias. Based on FDTD algorithm, a numerical modeling of powerd/ground plane with lumped elements is presented. The coupling effect between signal vias in power/ground plane with lumped elments can be analyzed by this model. Finally, coupling effect between signal vias under different conditions are discussed and some methods to improve signal integrity are proposed.