This paper describes fuzzy control theory to modulate the input signal for static Var compensator (SVC) to enhance power system stability. Static Var compensator, which is the first generation of FACTS devices, increases power transfer and improves the damping of electromechanical oscillations when used in transmission systems. The proposed control system for SVC is based on fuzzy set theory. The quantity of reactive power supplied and/or absorbed by SVC is determined based on the input signals at each sampling time. The effectiveness of the proposed control scheme is demonstrated by a single machine infinite bus system (SMIB) through computer simulations.