Abstract: Gap discontinuities appear in many stripline circuits, such as the multilayer microwave monolithic ICs and the interconnect systems in high-speed digital circuits. In this paper, a multilayer perceptron neural network(MLPNN) is used to model the gap discontinuities in stripline circuits. The MLPNN is electromagnetically developed with a set of training data that are produced by the full-wave finite-difference time-domain method. The full-factor design of experiments is used for determining the size of the training data.