The paper deals with studying the process of planning trajectories during the quadrotor flight. The typical trajectories of the drone flights have been analyzed. Block diagram of the control system in the nonholonomic case and the horizontal flight is given. Comparative analysis of the most widespread trajectories is represented. The possibility to use two types of Dubins trajectory is analysed. Introducing polar coordinates for forming flight trajectories is proposed. The grounded choice of the quadrotor trajectories for different cases of the holonomic and nonholonomic closed-loop control systems was proposed. The advantages and disadvantages of the trajectories planning in each of these cases were analyzed. The Simulink models for generators of the quadrotor trajectories have been developed. The simulation results of generations of these trajectories have been represented. The possibilities of MATLAB for simulating flight trajectories are shown. The obtained results can be applied for unmanned aerial vehicles of different types.