In this paper, the ESD protection circuit for p-GaN gate HEMTs with bidirectional clamp is proposed and investigated. ESD clamp circuits consist of several forward diodes in serials and a reverse diode. During the ESD pulse, a discharging channel in the proposed ESD clamp is built and the gate to source voltage for p-GaN HEMTs is clamped at safety value. Based on the experimental verification, the proposed ESD clamps have bidirectional protection functionality by being triggered by a required voltage and exhibit a high secondary breakdown current in both forward and reverse transient ESD events. Meanwhile, the proposed ESD clamp circuit can decrease the power loss in a static state.