The effect of temperature and relative humidity and their interaction on incubation period and hatching of the eggs of rice moth, Corcyra cephalonica (Stainton) within a temperature range of 15-40°C(at 5°C interval) and relative humidities of 30-90 percent (at 15 percent interval) was studied. As temperature advanced (35°C), the incubation period decreased (2.32 days) and as temperature decreased (15°C) the incubation period increased (11,22 days). Relative humidity alone had no effect on hatching and development of eggs. The combined effect of 35°C temperature and 90 per cent relative humidity proved to be congineal for the develop­ment (2 10 days).