Effects of water temperature on amount of oxygen uptake（V^^・o_2）and ciliary movement were examined in the Japanese hard clam Meretrix lusoria by rising the water temperature at a rate of 3℃ per hour from 10, 22 and 28℃ on Junuary, June, and August, respectively. The ciliary movement（CM）was measured with the transportation velocity of a piece of vinyl film put on the gill surface. V^^・o_2 and CM increased with rising temperature from 10, 22 and 28℃. However, V^^・o_2 and CM at 22℃ on June were larger than those when rising from 10 to 22℃ on January, and those at 28℃ on August were smaller than those when rising from 22 to 28℃ on June. From the results, the pattern of temperature compensation is supposed to be different between at 10-22℃ and at 22-28℃ : V^^・o_2, Precht type 4 or 5 and Prosser type I at 10-22℃ , and Precht type 3 and Prosser type II at 22-28℃.