Many insecticides were displayed failure of its effectiveness towards whitefly; in the reason of insecticide resistance and to facilitate and solve these problems, the mixing of the depressed insecticide with another insecticide which didn't lost the efficiency were considered helpful. A binary mixtures of commonly used insecticides for controlling whitefly Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) with five organophosphorous insecticides were bioassayed using leaf dip method to accomplish the most dependable mixture. As well as the potency evaluation on the whitefly field collection with all mixtures tested was gets a good shift in LC50s. Pirimiphos-methyl mixed with all other tested insecticides in ratio of 1:1exhibits the minimum potentiation ratio (PR) obtained in the study gave followed it the chlorpyrifos-methyl mixed in ratio of 1:10 and chlorpyrifos-ethyl in ratio of 1:4 ppm. The higher synergistic effect was obtained with four cases: cypermethrin, spinosad /fenitrothion 1:4 mixture and cypermethrin, deltamethrin / profenofos 1:10 mixture. Some insecticides combinations exhibit Potentiation Ratio was significantly below 1 (antagonistic effect) and in contrast some insecticides combinations exhibit PR were not significantly different from 1(additive effect).