The prevalence of microprocessor-based controllers in automotive systems has greatly increased the need for tools which can be used to validate and test control systems over their full range of operation. The objective of this paper is to develop a real time simulator of traction control system by the methodology of using hardware-in-loop simulation based on a personal computer. By use of this simulator, the analysis of commercial electronic control units and components for TCS were performed successfully. The simulator of this research can be applied to development of more advanced control systems(suck as vehicle dynamics control system) and other automotive system.