Three natural propolis derived from three different Egyptian regions (Alexandria, Dakahleya and Giza) containing different groups of antioxidants were tested as UV- protectants additives of Spodoptera littoralis nucleopolyhedro virus (SpliNPV) suspension, to prolong the virus activity. Theubromo cacao additive was tested as previously documented material that gives good protection. Screening results were based on bioassays, four main parameters were calculated Originally Activity Remaining (OAR) %, LIT₅₀ (Median Lethal Inactivation Time), Potency and Reduction % of the virus after exposure to UV source. This investigation had three steps, two at the laboratory and the last one was at the field. Field evaluation was during June to August 2015 on tomato plants at eastern farm of Faculty of Agriculture, Cairo University. Propolis additives reserved virus activity for 30.788, 46.407, 75.325 LIT₅₀ Hours for Alexandria, Dakahleya and Giza isolates; respectively. Theubromo cacao additive gave 58.011 LIT₅₀ value while the virus alone treatment was only 14.479 hour at the field. The obtained result demonstrated that certain propolis isolates gave better protection than cacao which may lead in the future to analyze the groups of antioxidants or flavonoids responsible for this protection.