Laboratory experiments were undertaken to study the relationships between the solitary endoparasitoid, Microplitis rufiventris Kok.and the Egyptian cotton leaf worm, Spodoptera littoralis (Boisd.) when fed on castor bean leaves treated with the bacterial, Bacillus thuringiensis Berl. And the fungus, Beauveria bassiana (Bals.)Vuill. with both entomopathogens Total developmental period, longevity of adults, six ratios and the percent of adults emergence of endoparasitoid, M. rufiventris were affected by treating host bacterial, B.thuringiensis caused mortality percentage of egg-larvae, using three rates recoded 20, 28 and 40%, respectively, compared with 4.0% in the control. For the fungus, B. bassiana, it was 8, 12 and 20%, respectively, compared with 1.0% in the control. But the biocide bioclean, B. thuringiensis + B. bassiana recorded 12, 28 and 32%, respectively, compared with 2% in the check. Emergence percentage of the parasitoid, M.rufiventris males were 32, 44 and 28%, respectively compared with 48% in the control. For females it was 32, 16 and 26%, respectively and 22% in the check. In case of fungus, B. bassiana the male's emergence percentage was 40, 52 and 52%, respectively, and 92% in the control. Percentage of Females was 40, 20 and 8%respectively, compared with 44% in the control. For M.rufiventris males parasitized the larvae of S. littorals that fed on castor bean leaves and treated with bioclean, B.thuringiensis + B. bassiana was 66,48 and 60% respectively, and it was 44% in control . For females it was 18, 12 and 4%, respectively, compared with 46% in the control.