The study was conducted in the Faculty of Agriculture / University of Baghdad 2015 - 2016 for the purpose of knowing the effect of oil extract of black pepper (Piper nigrum L.) in some aspects of life of different roles of cotton leaf worm Spodoptera littoralis (Boisd.) concentrations of 1.25, 2.5 and 5%. The highest percentage of egg hatching was 36.7% when exposed to 24-hour eggs to 5% concentration. The results showed that the larvae of the second phase were more sensitive to the oil extract and the highest percentage of Mortality was 32.6% compared with the sixth stage larvae, which were less affected. The effect of exposure to aromatic extracts was reduced in adult productivity. The number of eggs tested was 720.3, 885 and 917 eggs / female for each of the mature females from the treatment of larvae of the second and sixth stages and the comparative treatment, the percentage of egg hatch in each treatment was affected. When adults were exposed to the smells of the oil extract directly, they caused a 100% Mortality rate after 24 hours of exposure to 5% conc. while the adult mortality rate in the comparison treatment was 0%.