Abstract: Effects of temperature on oxygen consumption rate and ammonia-N excretion rate of the Southern Bay scallop Argopecten irradians ceucoutricus (1.6-4.8 cm in shell height,0.039 2-0.690 8 g in dry weight of soft tissue) were studied in laboratory from Dec.30,1996 to Jan.28,1997.Under the controlled conditions of ambient temperature 10-31℃ and salinity 32,the concentration of dissolved oxygen and ammonia-N were determined by the Winkler method and the hypobromite method respectively.Results show that the range of oxygen consumption rate was from 1.06 to 5.18 mg/ (g·h),mean of 2.35 mg/(g·h).The relationship between oxygen consumption quantity(mg/h)and dry weight of soft-tissue (g) can be represented by the allometric equation O=aW^b,b value was 0.748 2-0.937 3.The oxygen consumption rate increased with temperature increasing at 10-28℃,but reduced at 31℃.Effect of temperature on oxygen consumption rate (10-28℃) can be described by Os=r₁e^r2^t,r,the correlation coefficient was 0.194 0-0.944 0.The range of ammonia-N excretion rate was from 111.28 to 791.91 μg/(g·h),mean of 350.89 μg/(g·h).The relationship between ammonia-N excretion quantity (p.g/h) and dry weight of soft tissue can also be represented as the allometric equation:N=cW^d,and d value was 0.765 4-0.852 8.The ammonia-N excretion rate increased at the temperature from 10℃ to 31℃,and the impact of temperature on ammonia-N excretion rate can be represented by Na=q₁e^q2^t.r was 0.877 2-0.967 2.It is indicated that high temperature (31℃)can improve the level of protein metabolism in this experiment.The linear regression relationships among oxygen consumption quantity and temperature and dry weight of soft tissue can be described by O=-252.780+25.624t+1 509.917W,and ammonia-N excretion quantity by N=-38.758+2.794t+175.228W.the multiple r were 0.880 6 and 0.803 5,respectively.