Abstract: This study presents a control scheme based on a STATCOM to achieve damping enhancement of a grid-connected offshore wind turbine and Onshore Ower System. The operating characteristics of each of the WTGs are simulated by using ermanent-magnet synchronous generator while the Onshore Power System is imulated by a Synchronous Generator (SG) and fed to transmission lines. A damping controller of the STATCOM is designed by using PI controller to contribute effective damping characteristics to the studied system under different operating conditions. A time-domain scheme is used for both non-linear system model and linearized system model and subject to various disturbances are employed to simulate the effectiveness of the proposed control scheme. It can be concluded from the simulated results that the proposed STATCOM joined with damping controller is very effective to stabilize the studied SG-based Onshore Power System under various disturbance conditions.