Abstract: In order to thoroughly understand injection and production of waterflooding oilfield,calculation methods of accumulative water - intake rate of separate layer are studied. These methods can be used to provide basis for selection of practical separated layer development adjustment and production potential tapping measures and provide reliable accumulative water - intake rate data of separate layers for reservoir description. When water injection profile data are available, these data are used to calculate the accumulative water - intake rate of separate layers. When no water injection profile data are available, a dynamic calculation equation is established and the methods for selecting values of each parameter in the equation are studied Dynamic monitoring data verify that the calculation results of the dynamic calculation equation can reflect the real subsurface water intake rates. The accuracy of calculated accumulative water - intake rates are improved and can meet the requirements of production.