This paper presents the experimental work of airborne wind energy, kite system, as a power source, developed in Kyushu University. Kite extracts more energy from high altitude wind with less foundations compared with the wind turbines. This paper demonstrates the 7kW kite system of Kyushu University including the system’s design, tests, and experimental results. The kite system consists of inflatable wing with fixed tether length. The kite is controlled by small device, kite control unit (KCU), as a hardware-in the loop (HIL). This technique is utilized to develop and perform the real-time flight test of the kite. It provides an effective algorithm by adding the complexity of the system under control. Several tests had been performed to analyse the kite performance, and tension forces result from those tests are presented in different truck speeds and flight cases.