A field trial was conducted at the experimental station of Sindyon, Qalyubia, Egypt during the nili season of 2008. The effect of azadirachtin, cloves oil, damaseia extract, Orizon (acetampride + abamectin), Botany Gard (Beauveria bassiana), imidacloprid and profenofos (at a half of the recommended rate) on activity of some enzymes in Bemisia tabaci (Genn.) and Aphis gossypii (Glover) was studied, on cucumber (Cucumis sativus) variety (Hageen eshrak). After five days of the tested compounds application, the results revealed that these compounds had various effects on the activity of acid and alkaline phosphatases, α and β esterases, transaminases (GOT and GPT) and carbohydrates hydrolyzing enzymes )trehalase, invertase and amylase .( The enzyme activity reduced or increased significantly for some compounds in both insect species. Activity of acid and alkaline phosphatases, α and β esterases and GPT was more higher in A. gossypii than in B. tabaci, while the activity of GOT, trehalase, invertase and amylase was more higher in B. tabaci than in A. gossypii.