The toxicity of azadirachtin, pyridalyl and quercetin compounds were evaluated against the immature stages of the cotton leafworm, Spodoptera littoralis, field strain andlaboratory susceptible strain.The results showed that azadirachtin was the most potent tested compound flowed by pyridalyl and the least one was quercetin. Azadirachtin at 15.0 ppm achieved 30.4% mortality of treated egg masses, while pyridalyl and quercetin at the same concentration caused 28.8% and 21.2% mortality of treated egg masses, for lab strain, respectively, while field strain at the same concentration caused 23.4%; 20.4% and 16.4% mortality of treated egg masses respectively. The toxicity of tested compounds were evaluated against 2^nd and 4^th larval instar of S. littoralis, cleared that the toxicity of the tested compounds increased with increasing the exposure time, decreased by increasing the stage of larval instars. The larvae stop eating after two days of treatment. Also, the tested compounds shows no pupal mortality after 24; 48, and 72 hrs of treatment, but significantly increased percentages of deformed of adults. Results proved that the three natural compounds (azadirachtin, pyridalyl and quercetin), are potentially potent for control of S. littoralis, as antifeeding. Generally, natural compounds, will produce a new trend to increase toxicity of the newly hatched larvae of S. littoralis, enhance the role of beneficial insects. These compounds could be used in the IPM programmes, in order to minimize the negative effects of conventional insecticides on environment components and to protect the natural enemies.