Abstract: Based on the charge control theory,a accurate analytical model of I-V characteristics for AlGaN/GaN high electron mobility transistor（HEMT） is presented considering the relationship between self-heating effect and polarization,electron mobility,velocity saturation,conduction band discontinuity,doping concentration,channel temperature.The effect of parasitic resistances is also considered.The comparison between simulations and physical calculation shows a good agreement.The model is simple in calculations,suitable for design of microwave device and circuit.