In this paper Power system stability enhancement through static synchronous compensator (STATCOM)based controller is investigated. The potential of the STATCOM supplementary controllers to enhance thedynamic stability is evaluated. The design problem of STATCOM based damping controller is formulatedas an optimization problem according to the eigenvalue based objective function that is solved by a particleswarm optimization (PSO) algorithm. The controllers are tuned to simultaneously shift the lightly dampedand un-damped electro-mechanical modes of machine to a prescribed zone in the s-plane. The resultsanalysis reveals that the designed PSO based STATCOM damping controller has an excellent capability indamping the power system low frequency oscillations and enhance greatly the dynamic stability of thepower system. Manuscript profile