Laboratory experiments were carried out to study some biological aspects of the eleven spotted ladybird beetle, Coccinella undicempunctata L. (Coleoptera: Coccinellidae) reared on two aphid species (Aphis craccivora Koch. And Rhopalosiphum padiL.) at 25±2 ̊C and 65±5% R.H. A. craccivora proved as a better prey for C.undicempunctata rearing (shorter immature stages periods; 4.2,12.21,3.35 and 75.8 days for the periods of eggs incubation , larval and pupal periods and adults' longevity, respectively). The corresponding periods in case of rearing on R. padi were 4.72, 11.6, 3.6 and 68.4 days .The hatchability percentage among deposited eggs were 86.8 and 76.4%, respectively. The pre oviposition , oviposition  and post oviposition periods were 5.4 , 61.1 and 9.3 days on A. craccivora , opposed to 12.4 , 49.5 and 6.5 days on R. padi. .