Developments of the egg-plant stem borer Euzophera osseatella Triet (Lepidpterra :Pyralidae) was studied at constant temperatures 15,20, 25 and 30C0 ±1 C0 . Development of immature stages was accelerated as the tested temperatures increased. Total developmental time averaged 201, 93.43, 57.2 and 48.17 days at15, 20, 25 and 30C0 respectively. Generation period ranged between 205.6 and 49.17 days depending on rearing temperature. Adult female survived slightly longer than male. Fecundity was higher at (15C0) than 30C0. Female deposited 134.4 eggs at 15 C0, while this number drastically decreased to 62.0 eggs at 30 C0. However, egg hatchability (%66.25) showed a reversed trend. Thermal constant or threshold of development (t0) and thermal requirements (K ) degree- day (DDs ) were estimated to be 7.3 C0,11.43 C0 and 5.9 C0 for eggs, larvae and pupae, respectively. Based on estimated preferred temperature30 C0, heat units (U.T. ) 82.85, 413.6 and 538.55 are required to compled the development of egg, larval and pupal stages. Development of one generation may acquire 931.22. degree-days.