The present work was carried out to study the effect of exposure to different temperatures of 15, 20,25,30 and 35˚C and different host densities of 2, 4, 6, 8 and 10 larvae of the host on some biological aspect of Bracon brevicornis (Walker) (Hymenoptera: Braconidae)adult femaleswhen reared on Ephestia kuehniella full-grown larvae. Results indicated that exposure to different temperatures had a significant effect on pre-oviposition, oviposition, post-oviposition and longevity periods of an adult female, As the shortening of these periods was observed with a high temperature and vice versa. Also, a significant effect of temperatures on parasitism % and eggs laid / female were found. The obtained results showed an insignificant effect of host densities on biological aspects of an adult female of B. brevicornis, except in the case of Parasitism % and eggs laid /female.