Laboratory experiments were carried out to study certain biological parameters of the two predatory species Coccinella undecimpunctata L. and Chrysoperla carnea (Stephens) by rearing confinement on Aphis gossypii and Hyalopterus pruni. The total developmental time from egg hatching to adult eclosion were 18.85 + 0.26 and 21.60 + 0.2 days for C. undecimpunctata, while it was 26.16 + 0.56 and 24.42 + 0.29 days for Ch. carnea when fed on A. gossypii and H. pruni, respectively. Based on statistical analysis , the total developmental time showed significant difference between the two aphid species. The total consumption rate per C. undecimpunctata larva from the two aphid species were 190.05 + 4.75 and 246.55 + 7.26 aphids individuals and 172.45 + 6.24 and 623.18 + 41.80 Aphids individuals for Ch. carnea. When reared on H. pruni and A. gossypii , respectively. The average number of aphids consumed per larva for the two predatory species was also significantly different. There were a significant difference in longevity among females, longevity of males and the fecundity of their females of the two predators. The average numbers consumed from the two aphid A. gossypii and H. pruni during adult female of C. undecimpunctata were 3046.4 + 104.29 and 3797 + 124.72 aphid individuals, while adult males consumed 2478.9 + 66.19 and 2947.5 + 95.08 aphid individuals when fed on the two aphid species respectively. The average number of deposited eggs per C. undecimpunctata female was 181.1 + 5.97 and 301.9 + 7.3 eggs when reared on A. gossypii and H. pruni, respectively, while that was 327.73 + 31.19 and 459.43 + 24.57 eggs when Ch. carnea females fed on A. gossypii and Hyalopterus pruni during larval instars, respectively. The statistical analysis showed that the aphid species have a highly significant effect on the female fecundity.