Clearance rate and feeding of surf clam, Mactra veneriformis were determined for 5 different water temperature regime (5, 10, 15, 20, 25℃) and salinity regime (8, 14, 20, 26, 32 ‰) with small group (86.62 ± 7.10 mm in shell length) and large group (147.99 ± 10.83 mm in shell length). Clearance rate and feeding increased with water temperature up to 20℃, but rapidly decreased at 25℃. The minimal clearance rate and feedign was recorded at 5℃. surf clam showed low clearance rate and feeding at low salinity (below 20 ‰) and maximum values at high salinity (26-32 ‰).