An E-mode GaN MIS-HEMTs using multilayer La2O3/HfO2 as gate insulator is investigated for high power application. The multilayer La2O3/HfO2 composite oxide transformed to HfLaOx amorphous phase with low density of interface traps and border traps after post deposition annealing (PDA) at 6000C as judged from the C-V characteristics of the HfLaOx/GaN MOSCAP. The device exhibits a low ON-resistance of 11.5 Ω·mm, IDSS of 455 mA/mm, and Gm,max of 140 mS/mm. The threshold voltage (Vth) is stable without hysteresis during the gate voltage sweep. Overall, the E-mode GaN MIS-HEMTs demonstrates a very good interface quality between the HfLaOx film and AlGaN layer, which results in excellent device characteristics for power switching application.