The cotton leafworm, Spodoptera littoralis Boisd. is considered the most dangerous insect pest which threat the early sugar beet plantations. Because the conventional insecticides lead to much hazards to natural enemies, it has been important to find out other alternative safe technique. The current investigation was conducted at sugar beet fields in  2013 and 2014 seasons at Shenno village (Kafr El-Sheikh Governorate) for evaluating the effect of one conventional compared to insect growth regulators (anti-moulting) on larval mortality of S. littoralis and their side effects on certain predators mainly (Chrysoperla carnea Setphens and true spiders). Field tests proved that the insect growth regulators  caused high reductions in larvae populations, ranging between  93.39 and 94.98% where are almost the same with conventional one (94.88%) . The insect growth regulators caused a low reduction in Chrysoperla carnea and true spiders populations (35.54 – 40.51%), while the conventional insecticide caused a high reduction in these predators by 93.39%. This investigation show that the insect growth regulators were efficient in reducing the larvae populations of S. littoralis, and in the same time caused a low reduction on predators in comparison with the conventional one.