Abstract: Chang 81 reservoir of Bai 306 block in Baibao oilfield is divided into three little layers,and the researched on flow units should be studied.According to the log data of thickness,porosity,permeability,the production of thickness and permeability,shale content,FZI and oil saturation,with the method of cluster analysis,the research block have been divided into four types of units E,G,M,P.In order to prvoe the validity of the result,used the regression analysis and discriminant analysis to get the discriminant function of the flow units and the index range of every flow unit.Combined with the dynamic production data of oilfield,the results indicate that the properties,oil-bearing,sedimentary facies of the flow units has the good correlation with its production capacity.This is a good guide to production and development of oilfield.