The thesis is to design a tailless UAV and its guidance, navgation and autopilot systems. Procedure of UAV design uses standard aircraft design procedure which includes concept design, preliminary design and detail design. The configuration and structure of UAV depend on the performance reqirements. Attitude control uses state feedback control and LQ criterion to design control gain. The MATLAB® is implemented to simulate the control responses. The ARM® and PIC® microcontrollers are used to build up the avionics and ground control station.