This paper presents a design for a fuzzy controller for low frequency oscillations using the improved virus colony search. In this way, the parameters and fuzzy members are considered variably, which ultimately has turned into an optimization issue. Therefore, the proper coordination between these variables leads to the best operating conditions and vice versa: inappropriate adjustment of the parameters may lead to a persistent exacerbation in applying controlling signals. Because of the complexity of the system and to avoid a large amount of computing, in this paper, optimization of control parameters has been proposed with the help of an improved virus colony search algorithm. The proposed controller has been studied under different operating conditions considering the interregional fluctuation and low frequencies. It is shown that the proposed fuzzy controller has a better performance for stabilizing damaging system disturbances in bad operating conditions.