Abstract: This paper gives an overall discussion on the Neural Network Expert System and its development steps.Taking the reservoir and crude oil parameters and daily output per well for 10 available oil wells in Shengli-Fanjia oil field for example,the Neural Network Expert System developed has been used successfully to predict the daily output per well of two forecasting wells.Therefore,the Neural Network Expert System can overcome the defects of conventional statistical method and fuzzy method who are unable to correctly determine the subordination degree and jurisdiction distribution of each parameter.It is also pointed out that the oil field prediction by the Neural Network Expert System is accurate,rapid and effective.