Abstract: From the relationship between the surface wind vector and the sea surface brightness temperature parameters at difference polarizations, the influence of the windfield on the brightness temperature was quantitatively analyzed using the Windsat satellite L2 wind field data and the L1C satellite SMOS data in the Northwest Pacific region of China on May 1, 2014.The results indicate that the wind speed has greater influence on the sea surface brightness temperature than the wind direction; the sensitivity of wind field is the most conspicuous in the vertical brightness temperature, and the Stokes2 brightness temperature parameter has the lowest sensitivity to the wind speed, meanwhile the Stokes1 brightness temperature parameter has the lowest sensitivity to the wind direction under 20 degrees; the best correlation between sea surface brightness temperature and wind field is under 3 level wind speed and 0~150 degree wind direction; the significant brightness temperature fluctuation mainly happen over 6 level wind speed and 300~360 degree wind directions.