In this paper, a multi-pulse dynamic resistance testing method for GaN devices in different operating modes is proposed. Dynamic resistances in 1st and 3rd quadrants of two different devices are measured under hard- and soft-switching conditions. Results show different behaviors of these two devices. One of the device’s dynamic resistance recovers faster in the 3rd quadrant than in the 1st quadrant, while the other shows quite different characteristics. So, operating modes in both 1st and 3rd quadrants should all be considered when evaluating the dynamic resistances of GaN power devices.