Although production system and material handling system of TFT-LCD fab are closely interconnected, the simulations of two systems have been carried out independently. In this paper, a framework for integrating production simulation and material handling simulation of TFT-LCD fab is suggested. The integrated simulator can be subdivided into the control system and the application system by the software layer. The control system is based on formal models of the target TFT-LCD fab and the application system can be implemented on top of any 3D visual simulator that has TCP/IP socket connection feature. The integrated simulator is expected to provide more reliable analysis of the TFT-LCD fab by including interactions between the production system and the material handling system more rigorously.