This paper presents a mathematical formulation of the optimal VAR source control problem in power system. This method employs a linearized objective function and constraints, and its approach is based on adjusting control variables. Transmission losses are considered as a function of voltage increments are related by modified jacobian matrix. Revised linear programming is used to calculate the voltage increments which minimize the transmission losses, and adjustments of control variables are obtained by a modified jacobian matrix. This method does not requires any matrix inversion, it will save computation time and memory space, The proposed algorithm is applied to Ward-Hale 6 bus test system and numerical results verify the proposed method over the existing ones. © 2014 Elsevier B.V., All rights reserved.