This paper described the electronic performance of power module packaged high-power AlGaN/GaN high electron mobility transistors (HEMTs) on silicon substrate. Twelve GaN HEMTs chips are mounted on AlN substrate. Each device is wire-bonded in parallel connection to increase the power rating. Both DC and pulsed current-voltage (ID-VDS) characteristics are measured with different connection and sizes of devices, at various power densities, pulse lengths, and duty factors. The packaged GaN HEMTs exhibit the pulsed drain current, 0.43 A/mm. The performance of packaged multichip GaN HEMTs power module is studied. The GaN HEMTs power module exhibit a drain current of 23.04 A, which indicates that connecting GaN HEMTs devices in parallel can effectively increase the drain current.