Wintertime geostrophic winds (&ngr;↘g), calculated over the East China Sea from surface pressure maps, are compared to observed winds (&ngr;↘0) from the region. For mean winds, the average counterclockwise veering angle from &ngr;↘g to &ngr;↘0 is 37¿. and the average reduction in amplitude is 39%. For fluctuating winds the average veering and attenuation are 25¿ and 55%. The greatest reduction occurs for land stations, while the lowest (33%) occurs at an offshore buoy station. Evidence from the power spectral computations suggests that the spectral contents of &ngr;↘g and &ngr;↘0 are very similar, even for cases where observed winds are of much lower amplitude and do not appear to be reliable.