Insecticide penetration enhancing involves utilizing one or more active agents from insecticides, tributoxyethyl phosphate (TBEP) in dosages of 2.5-150.0 g/ha and one or more ionic and non-ionic emulsifying agents and their mixtures with hydrophilic-lipophilic balance (HLB) values of 10-17. All the components are applied simultaneously or sequentially on the plants attacked by harmful organisms.