Temperature and UV light can have a highly detrimental effect on entomopathogenic fungi, potentially resulting in conidia destruction. Formulations can aid in shielding these fungus structures from high temperature and radiation. The goal of this investigation was to prepare Beauveria bassiana oil-based formulation and assess the impact of different storage temperature and ultraviolet radiation on their potential pathogenicity on Spodoptera littoralis. the findings demonstrated that addition of Sun flower to fungal spore increase their infectivity to Spodoptera littoralis, formulations stored at refrigerator recorded higher mortality percent when compared to formulations stored at 37ₒC and inverted emulsion formulation enhance tolerance of fungal spore to UV radiation for 4 hours .the overall mean of total percentage larval mortality vertically increased dramatically as the concentration of the formulated conidia climbed to 37.19, 44.06, 51.87, and 61.25% at the concentrations of 25, 50, 75, and 100%, respectively.In contrast, the overall mean of total percentage larval mortality horizontally decreased significantly with increasing the storage period as it decreased to 47, 43.5, 41.5, 36.5, 33.5, 31 and 28.5% at the first, second, third, fourth, eighth, twelve, and sixteenth week of the storage periods, as opposed to 57.5% in the zero-time treatment, respectively.