Abstract: An accurate prediction of the reservoir performance is an inportant basis for the design and adjustment of an oil field development program and an optimum control of its production. Based on the theory of fuzzy control and integrated with the concepts of system theory, information theory and cybernetics a study on the prediction and artificial control ofthe reservoir perfomance is carried out. The reservoir is considered as a fuzzy(vague)system and the fuzzy input/output information is studied by an inverse problem of fuzzy inference of the first kind. Next, thestate structure is described as a fuzzy control relation(R_t)and a fuzzy control prediction method for reservoir behevior indexes is suggested. And optimum control of reservoir performance is discussed. Finally the application of this technique is demonstrated by taking an oil field and a gas well as examples.