The present work is the studying the toxicities of three insecticides from different groups indoxacarb, emamectin benzoate and methoxyfenozide on Tuta absoluta. collected from field.The obtained result showed the toxicity of three insecticides against the third larvae instar of  T.absoluta, the  values of  LC₅₀  for  methoxyfenzoid, indoxacarb and emmamectin benzoate  (50.77 ppm. , 2.33 ppm. and 0.022 ppm.), respectively.  Emmamectin benzoate and indoxacarb are more effective methoxyfenzoid. The biochemical result showed high increase in activity enzyme trehalase and Acid phosphatase (17.93% , 7.83%), respectively and slight increase in invertase and amylase activities, (2.51%, and 0.039%), respectively, when treated by Indoxicarb  comparing with the other two insecticide.