The inkjet head ejection performance evaluation method includes: printing a test pattern for examining an ejection condition for each nozzle by an inkjet head having a plurality of nozzles arrayed in a matrix and is read by an image reading device; and measuring a depositing position for each nozzle from the read image to calculate a deposit displacement amount based on the depositing position and pattern information, wherein a position of a center of gravity in a Y direction of nozzles used for calculation for calculating the deposit displacement amount of the nozzle number n is equal to a position of a center of gravity in the Y direction of all nozzles existing in the nozzle range of the nozzles used for calculation, where a direction of relative movement between the inkjet head and a recording medium is the Y direction.