RPM is an important ancillary service, especially in deregulated energy environment which contains two major areas: reactive power purchase and reactive power dispatch. Various technical and economic issues need to be considered in this market. This work shows RPD as the main optimization problem. As optimized electric power dispatch is important problem in electrical power systems. Cost infimumization, voltage stability improvement, losses minimization, and terminal voltage deviation minimization are important functions used to solve ORPD as single objective function (SOF) optimization problem. Various classical methods and several evolutionary computing based optimization techniques are used to solve this ORPD problem. In this study, Genetic Algorithm (GA) is used to solve this ORPD. In this work, algorithm had been put forward for acceptance and was tested on the standard IEEE 24 bus system and programming was done in MATLAB software. Result of ORPD problem is presented for the best values as a single objective function (SOF) compare for IEEE 24 bus system.