Abstract: In view of the disadvantages of dual - volumetric single- range metering method used in oilfield, a new dynamometer diagram method is presented for metering well yield. Time - varying load and displacement data of pump rod are recorded by wellhead sensor and are used to determine the effective stroke of pump. Then the built - in mathematical model of the equipment is used to calculate well yield. This metering method has been applied in 17 wells of Changqing oilfield and the average error of calculation results is 6. 37%. It can meet the technical needs of well yield metering that are presented along with enlarging production and construction scales of oilfield. In addition, it can simplify surface technological process and lower cost of investment.