The aim of the study was to investigate the effect of an adjustable vacuum distribution device on seed pick-up similarity of a multiple-rows pneumatic plate metering device due to unequal rows performance. A completely vacuum opened angle of the device (30°), Six vacuum opening angles (5°, 10°, 15°, 20°, 25° and 30°) and different angles set up on rows (4°, 7°, 10° and 30° through row 1,2,3, and 4, respectively) were separately examined at six rotating speeds. Results revealed that under same speed and same vacuum opening angle, an increase in vacuum provided more consistent rows pick-up, while increase in angle increased rows pick-up coupled with the increase in their variation. Row1 and row4 generally tend to have the highest and lowest seed pick-up, respectively, under most of investigated angles and speeds. Rows consistency CV declined under the increase of both opening angle and velocity. Results of different rows angles set up were found to be better than those of the same angle. Different rows angles resulted in better rows CV value of 2.01%, 1.78%, 1.89%, 1.34%, 1.77% and 2.45% at speed of 5, 10,15,20,25 and 30 r.min-1, respectively. Results concluded that vacuum distribution device could be acceptably used for improving rows performance, but further studies are necessary to develop an outside-control method for easy application.