The effect of temperature and salinity on the photosynthetic and respiratory rates of some seaweeds are reported. The regression equations for the seaweeds and their correlograms are discussed and compared.The results indicate that the photosynthetic rate of E. binghamiae fronds shows a significant negative linear correlation (p<0.01) with changing of temperature (20-35℃), the optimum temperature being 20℃, while for the others there is a conic correlation between photosynthetic rate and temperature.The optimum temperature for photosynthesis is 23-25℃ for two species of Porphyra fronds, 25-28℃ for Gracilaria sp. thalli and 23-30℃ for V. conglobata and S. hemiphyllum fronds, separately. The rates of respiration for all the studied species increase linearly with increasing temperature from 18 to 35℃. The optimum salinities for photosynthesis range from 26 to 32 for two species of Gracilaria, whose respiratory rates decrease gradually with increasing salinity. The effect of temperature and salinity on the photosynthetic and respiratory rates of some seaweeds are reported. The regression equations for the seaweeds and their correlograms are discussed and compared. The results indicate that the photosynthetic rate of E. binghamia fronds shows a significant negative linear correlation (p <0.01) with changing of temperature (20-35 ° C), the optimum temperature being 20 ° C while while for the others there is a conic correlation between photosynthetic rate and temperature.The optimum temperature for photosynthesis is 23-25 ​​° C for two species of Porphyra fronds, 25-28 ° C for Gracilaria sp. thalli and 23-30 ° C for V. conglobata and S. hemiphyllum fronds, separately. The rates of respiration for all the studied species increase linearly with increasing temperature from 18 to 35 ° C The optimum salinities for photosynthesis range from 26 to 32 for two species of Gracilaria, whose respiratory rates decrease gradually with increasing salinity.