Laboratory experiments were carried out in plant protection research Institute, Sharkia Branch, to study, some biological aspects and predation efficacy of the predator, Coranus aegyptius (Fabricius) (Hemiptera: Reduviidae) which recorded  last decades on several economic and wild plants in El-Khattara  district, Sharkia Governorate, Egypt, during 2012 and 2013 years. Some biological aspects and predation of this predator was investigated using the second larval instar of the cotton leaf worm, Spodoptera littoralis  (Boisd.) as restricted prey under the conditions of 30 + 1ºC and 65 + 5% R.H.  Egg stage incubation period lasted 7.30 days for the male and female. The five nymphal instars were  recorded. The total developmental period and adult longevity were shorter in case of male 36.86 and 21.2 days, respectively than in case female, it were 38.85 and 61.2 days, respectively. Pre, oviposition and post ovipostion periods were 4.4, 50.7 and 6.6 days, respectively. The feeding capacity of nymphal stage and adult were 219.15 and 744.3 S. littoralis, larvae  respectively for female. Its were 200.0 and 236.7 larvae respectively in case of male. The total number of deposited eggs were 220.5 + 11. 69 eggs, throughout an ovipositional period of 50.7 + 3.93 days. These results showed that C. aegyptius can play an important role in biological control of cotton leaf worm  S. littoralis  in the field in economic crops in Egypt.