This paper deals the HVDC system stability according to controller types. In this paper, in order to evaluate the stability, some important properties of the HVDC. such as $d{ au}/d{alpha};,;dV/d{alpha}$ and dP/dI stability in different control modes, are analysed. Furthermore, Maximum available power according to controller types are calculated. This paper shows a generated formulation of control sensitivity for control modes, aids in the design of the controller and the operating mode determination. Finally, a simulation is performed by Math/CAD, and a simulation results are verified.