Effects of water temperature on ventilation was examined in the black-lip pearl oyster Pinctada margaritifera. The water temperature rose at a rate of 3℃ per hour from 20℃ on June and of 2℃ per hour from 27℃ on July. Ventilation volume was increased with rising temperature from 20℃ (June) and 27℃ (July) to 29℃. However, the ventilation volume at 27℃ on July was the same as that at 20℃ on June. From the results, the temperature compensation pattern is supposed to be Precht type 2 (Complete response) and Prosser type II (Translation).