Abstract: The magnitude and diurnal variation of the turbulent drag coefficient CD and bulk transport coefficient of heat (or moisture) flux. CH (or CE),have been studied by using the wind speed and temperature gradient data of meteorological towers. It' s shown that the CD, CH (or CE) can be about one order in greater over rough land surface than over sea surface. There are obvious diurnal changes of these coefficients. Their responses to the changes of dynamic roughness are sensitive.