With Huangdao Doppler radar products and the buoys data near sailing spots durin g Good Luck Beijing2006 Qingdao International Regatta, a case that the wind sp eeds near sailing spots decreased suddenly is analyzed to study the Doppler rada r features for the change of the surface wind speed. Results show that there is a shear layer of the wind field around the convective system. The height of the shear layer changes with moving and development of the convective system. When t he height of the shear layer falls and the wind speed near the shear layer decre ases,[KG*4/5] the wind speed near the sailing spots also decreases.Afte r the shear layer rises,the wind speed near the sailing spots increases too. T his phenomenon indicates that the height of the shear layer can affect the wind speed near the surface. The Doppler radar VAD Wind Profiler products can reflect the vertical change of the shear layer and wind speed, which is a good indicato r of the change of surface wind speed.