This paper presents a output tracking design for regulating the load voltage of the electric power system. Based on a model of electric power system proposed by Dobson and Chiang (1988), the saddle-node bifurcation and Hopf bifurcations were observed (Wang, et al, 1994) by treating the reactive power as system parameter. Those bifurcations were found to lead to the appearance of the dynamic or the static voltage collapses of the power systems. In construct to the state feedback design at the bifurcation point via the tuning of the Static Var Compensator as proposed in (Saad, et al, 2005), a sliding mode control (SMC) scheme using SVC was employed in this study to construct a load voltage tracking design control law for regulating the load voltage and hence providing the stability of electric power systems. The numerical simulations demonstrated that the proposed control scheme not only could provide the regulation of the load voltage but also prevent and/or delay the appearance of bifurcation phenomena and chaotic behavior.