In the context of the data of atmospheric turbulence observed over the Nansha islands sea region,investigation is performed of aerodynamic roughness length(z0) and neutral drag coefficient(C_DN),by use of Brutsaerts hypothesis,the formulas which are used to get bulk exchange coefficients(heat transfer coefficient CHN ,water vapor exchange coefficient C_EN) are derived both over the smooth and rough sea surface.On this basis,the distributions of aerodynamic roughness length,drag coefficients and bulk exchange coefficients with the wind speed(u) at the height of 9.4m are discussed and some interesting results are obtained.