Unlike the insulated gate structure of the Si-based metal-oxide-semiconductor field-effect transistors (MOSFETs), the gate of p-GaN-enhanced high electron mobility transistors (HEMTs) is a p-n junction, which is highly conductive under a large forward bias condition. The traditional method for the gate charge assumes that all current is injected and stored as gate charge. Thus, it is not applicable to p-GaN HEMT devices because the parameter values would be significantly overestimated. In this study, based on the basic accumulation process of the gate charge, we propose a dynamic capacitance method to extract the gate charge parameters of p-GaN E-HEMTs, which can reduce the impact of the forward leakage current. The capacitance method produces an ideal Miller plateau and characteristic curve, indicating significant potential for practical application.