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 (16℃, 20℃, 24℃, 28℃ and 32℃). The results are summarized as follows: 1. The developmental periods from the egg to the adult emergence of two parasitoids became shortend as temperature became higher. 2. The developmental zero of T. chilonis and T. ostriniae were 11.1℃ and 11.7℃, respectively. The effect heat units required from the egg to the emergence of adult of T. chilonis and T. ostriniae were 121.2 day-degree and 134.7 day-degree, respectively 3. The percentage of emergence of two parasitoids developed on the egg of Ephestia kuehniella were higher than those on the egg of Plutella xylostella.