In the Asian brown mussel, Modiolus metcalfei, the oxygen uptake was examined under normoxic condition at 15.2℃. The ventilation volume per body weight (TW), wet weight of soft part (WW) and dry weight of molluscous part (DW) were 2.13l/min/kg TW, 5.23l/min/kg WW and 37.7l/min/kg DW, respectively. Oxygen utilization was 2.5%. Amount of oxygen uptake were 0.215ml/min/kg TW, 0.530ml/min/kg WW and 3.76ml/min/kg DW.