The National Oceanic and Atmospheric Administration (NOAA) Polar Orbiting Environmental Satellites (POES) High Resolution Picture Transmission (HRPT) data in the Northwest Pacific Ocean has been acquired through the SeaSpace ground station located at the Ocean University of China since October 2000,and these data have been processed by the TeraScan system.The sea surface temperature (SST) products in the Northwest Pacific Ocean derived from Advanced Very High Resolution Radiometer (AVHRR)are evaluated.We compared the SST products with the buoy SSTs during the stable operational period of each satellite.There are a total of 33715 and 71819 matchups acquired for daytime and nighttime,respectively,between the NOAA/AVHRR SSTs and buoy SSTs.For each satellite,the biases and standard deviations at daytime are smaller than those at nighttime.The monthly biases at daytime generally oscillate around 0 ℃,except for NOAA-15.By contrast,the monthly biases at nighttime mostly oscillate around-0.5℃.Both daytime and nighttime biases exhibit seasonal oscillations for all satellites.The seasonal biases of the SST difference at daytime between each satellite and buoy are mostly within ±0.25℃,except for the negative bias of-0.58℃ in May for NOAA-18.The seasonal biases of the S ST difference at nighttime are mostly around-0.5 ℃,and NOAA-16 has a lower bias,i.e.,-0.86℃,in April.These results indicate that the accuracy of the SST products is inconsistent for each satellite during different periods.It is sug-gested that the NOAA/AVHRR data should be reprocessed to provide highly accurate SST products.