Abstract: Pattern recognition methods,capable of advanced decision making without a precise description of the process model,have been used in many cases to implement advanced control systems.Such techniques have been applied to structural identification of nonlinear systems and distributed parameter systems,direct control of systems operating in unfamiliar environments,and dynamic modelling,state estimation,optimizing,fault diagnosis,predictive control,self-tuning control,intelligent control and so on.An account of these techniques and their application to controls is given in this paper.Possible new applications of pattern recognition to process control systems are suggested.