DC parameter extraction of a novel high linearity Al 0.27 Ga 0.73 N/AlN/ Al 0.04 Ga 0.96 N/GaN HEMT with composited-layer and unintentionally doping barrier is presented. The devices with gate length of 0.3µm and T-shaped gate width of 1000µm are designed and fabricated. EEHEMT1 model is adapted to DC parameter extraction by using software of ICCAP. Comparison between measured results and simulated results shows extracting parameters of EEHEMT1 model are in good agreement with measured results.