The effect of temperature on the development of two egg parasitoids, Trichogramma chilonis and T. ostriniae, which attack the diamondback moth, were observed in the laboratory under the controlled conditions of constant temperatures (20℃, 24℃ and 28℃). The results are summarized as follows: 1. The longevity of the female adult of T. chilonis was significantly longer at 20℃ as compared with 24℃ and 28℃. 2. No significant difference in the female adult longevity of T. ostriniae was observed at 20℃, 24℃ and 28℃. 3. The fecundity of each parasitoid was significantly higher at 20℃ as compared with 24℃ and 28℃. 4. The two parasitoids were proved to be pro-ovigenic. 5. The percentage of offspring female production in the two egg parasitoids was highest from the eggs deposited on the first day of emergence and the trends were decreased thereafter towards the end of female's lifetime. 6. The values of capacity for increase (γ_c)risen as the temperature increased from 20℃ to 28℃. 7. The fecundity of each parasitoid was highest at the first day of emergence and then the trend was decreased toward the end of female lifetime.