The wind data from ASCAT were compared with those of HY-2 satellite, and their accuracy were verified with the data from oil platform in the northern South China Sea, which were collected from Jul. 19, 2011 to Sept. 17, 2012. The RMS (root-mean-square error) between ASCAT wind speed data and the platform-measured wind speed data is about 2.53 m/s. The RMS between ASCAT wind direction data and the platform-measured wind direction data is about 47.87°. The RMS between HY-2 wind speed data and the platform-measured wind speed data is about 3.41 m/s. The RMS between HY-2 wind direction data and the platform-measured wind direction data is about 58.66°(The temporal and spatial differences between the ASCAT and HY-2 date were limited to less that 30 min and 25 km). With the temporal and spatial differences between ASCAT and HY-2 date were limited to less than 150 min and 15 km, the RMS between ASCAT wind speed data and HY-2 wind speed data were also calculated in this paper, which were about 0.72 m/s. The RMS between ASCAT wind direction data and HY-2 wind direction data were about 8.50°. In conclusion, the measured data of ASCAT were a little better than those of HY-2, and it provide a basis for using seawind data of satellite in the northern South China Sea.