The present study was conducted to evaluate the effect of the field recommended rate of five commercial acaricides namely Ethion, Fenpyroximate , Etoxazole, Chlorfenapyr and Abamectin on some biological aspects of the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) and its predator Phytoseiulus persimilis Athias- Henriot. Both predator and prey were proceeded under laboratory conditions at 28 ±2 °C. Results showed significant differences among the five developmental treatments and control in the duration of male and female of P. persimilis and T. urticae after treating eggs with certain acaricides.The results also revealed that Abamectin was the most effective acaricide on growth index, developmental rate and mean survival percentages of immature stages of T. urticae female. On the other hand, Chlorfenapyr was the most effective acaricide on growth index and mean survival percentages of P. persimilis immature stages, while Abamectin was the most effective of female, acaricide on its developmental rate.