Abstract: The Austausch coefficient may be obtained by wind structure.1902 Ekman established the wind spiral theory in the friction layer.From the observed wind spiral,we may calculate of the Austausch coefficient by this theory.1952 Лайхтман considered effect of the change of pressure field with height; i.e.the thermal wind effect,and found excellent results.But,Лайхтман's Formula holds only for the condition in the stationary current flow,or in the stationary temperature pressure field and uniform temperature pressure gradient.In this paper,we consider the unstationary efteas calculating the Austausch coefficient in the friction layer,and obtain a more general formula.Under some special constrains,it tends to be the nasxnax or Fkman's formula.Then,this formula may be more accurate in calculation and more wide in application.some calculations based on observed data by using these three different formulas are presented and compared.