In this study, a nonlinear adaptive control system for a single-rotor type small helicopter is designed. First, a small autopilot device, which can be applied any singlerotor type helicopters, is developed based on FPGA (Field Programmable Gate Array) board. In the case of small helicopter, the payload limitation is so tight. Therefore, we can only use small and light weight sensors and computer for the control. All the sensors we use for the autopilot device are light enough to be mounted on any small helicopters. the total weight of the autopilot device with box is about 300 g. Next, a nonlinear adaptive attitude controller for small helicopter is designed by using adaptive backstepping method. It is guaranteed to make the attitude of the helicopter follows arbitrary time varying reference attitude, even when the helicopter model has the parameter uncertainties, such as inertia moment or aerodynamic uncertainties. Finally, the effectiveness of the autopilot device and the adaptive attitude controller are verified by simulation with parameter uncertainties, and the flight experiment using heterogeneous small helicopters.