Among of the apple pests, the mites are of particular importance, and among the mites the Cenopalpus irani Dosse from the Tenuipalpidae family and the Eotetranychus frosti McGregor from the Tetranychidae family have large populations in western Iran. Predatory mite, Typhlodromus bagdasarjani Wainstein & Arutunjan is a natural enemy of these mites that collected from infested trees to these pests. In this study, the reproductive parameters of T. bagdasarjani feeding on E. frosti and C. irani were determined at 25±1°C, with 16:8 h L: D, at an average daily relative air humidity of 60±10% on apple leaves. The results indicated that the highest and lowest values of the gross fecundity rate were 24.38 ± 1.99 eggs on E. frosti and 17.22 ± 2.20 eggs on C. irani. The gross fertility rate and net fertility rate of T. bagdasarjani were higher on E. frosti than when fed on C. irani diet. The net fecundity rate and daily fertile eggs per female on E. frosti and C. irani were 20 ± 1.63 and 13.26 ± 1.69 eggs/ female and 0.46 ± 0.03 and 0.34 ± 0.04 egg/female/day, respectively. The reproductive value (Vx) of T. bagdasarjani fed on E. frosti was higher than of individuals fed on C. irani. The value of this parameter was 12.14 and 11.59 females/female on E. frosti and C. irani, respectively. The results of this study suggested that E. frosti is a suitable prey for T. bagdasarjani, and that the predator might play a significant role in preventing that prey from reaching even higher population levels than it does on apple in western Iran.