Effect of density-independent factors (minimum-maximum temperatures and relative humidity) and density dependant factors ( plant age and natural enemies; Coccinella undecimpunctata, Chrysoperla carnea, Syrphus corolla, Eretmocerus eremicus and Orius laevigatus) of the environment on the population dynamics of Silverleaf whitefly, Bemisia tabaci (Genn.) and potato leaf hopper, Empoasca fabae (Harris) attacking potato plant Solanum tuberosum at El-Gharbia governorate, Egypt were investigated on autumn and spring plantation of 2019/2020 &2020/2021 seasons. The results revealed that the population fluctuation of B. tabaci & E. fabae recorded the highest infestation in December during both autumn seasons, while in both spring seasons the highest peak for the two pests was reached in May. The combination of abiotic and biotic environmental factors on population densities of B. tabaci and E. fabae was effective as the explained variance (E.V.) values were (88% -92%) and (85% -86%) for B. tabaci, while E.V. was (94% _ 91%) and (92% -77%) for E. fabae during autumn and spring of the plantation 2019/2020 &2020/2021 seasons, respectively. The present research can be helpful to the ecological characteristics of main potato pests to obtain more effective pest management.