In this paper we present a novel approach to modeling AlGaN/GaN high electron mobility transistor(HEMT) with an artificial neural network(ANN).The AlGaN/GaN HEMT device structure and its fabrication process are described.The circuit-based Neuro-space mapping(neuro-SM) technique is studied in detail.The EEHEMT model is implemented according to the measurement results of the designed device,which serves as a coarse model.An ANN is proposed to model AlGaN/GaN HEMT based on the coarse model.Its optimization is performed.The simulation results from the model are compared with the measurement results.It is shown that the simulation results obtained from the ANN model of AlGaN/GaN HEMT are more accurate than those obtained from the EEHEMT model. In this paper we present a novel approach to modeling AlGaN / GaN high electron mobility transistors (HEMT) with an artificial neural network (ANN). The AlGaN / GaN HEMT device structure and its fabrication process are described. The mapping (neuro-SM) technique is studied in detail. The EEHEMT model is implemented according to the measurement results of the designed device, which serves as a coarse model. Ann ANN is proposed to model AlGaN / GaN HEMT based on the coarse model. Its optimization is performed. The simulation results from the model are compared with the measurement results. It is shown that the simulation results obtained from the ANN model of AlGaN / GaN HEMT are more accurate than those obtained from the EEHEMT model.