The present work was carried out to study the population abundance, biology and efficiency of the coccinellid predator Clitostethus arcuatus (Rossi) when fed on pomegranate-whitefly, Siphoninus phillyreae (Haliday) at Kafr El-Sheikh region during two successive seasons 2006 and 2007. S. phillyreae and its related predator C. arcuatus appeared together during May to June. The period from August through October considerable of the pest and its related predator C. arcuatus. Duration of the first, second, third, fourth larval instars and prepupae of the predator averaged were 1.2, 2.2, 2.6, 2.8 and 1.1 days, respectively. The total larval period, pupal stage at total developmental period averaged 3.6, 9.9 and 17.8 days, respectively. Adults, male and female averaged 69.2 and 103.1days, respectively. C. arcuatus larval consumed an average total number of 319.8 eggs. The adults male and female consumed an average number of 4237.6 and 5486.6 of S. phillyreae eggs, respectively.