Abstarct: This thesis presents a model reference adaptive control methods for longitudinal channel of Surveillance Unmanned Aerial Vehicle (UAV). The surveillance UAV used in this thesis is a hybrid UAV. The control of hybrid UAVs is of particular importance because these UAVs have propulsion systems in vertical and horizontal direction. In the proposed model reference adaptive control method, the matrices of the system parameters are considered unknown and constant, only the sign of all leading principal minors of high frequency gain matrix are assumed to be known. The adaptive law is baxsed on Lyapunov function that ensures closed-loop system stability and asymptotic output tracking. The parameterization used in this method is baxsed on decomposition of the high frequency gain matrix as SDU form where S is a symmetric positive definite matrix, D is a diagonal matrix and U is a unity upper triangular matrix. In this method, the signal including the output tracking error and its derivatives is used instead of the output tracking error signal which has made its more accurate.