Abstract: The well-known resistance lawis suitable for stationary and homogeneous PBL.In this paper,the resistance law was extended to non-stationary and inhomo geneous conditions by using the real wind in free atnosphere instead of geostro phic wind.The main characteristics of the internal parameters of the PBL and similarity functions are thus obtained in non-stationary and in homogeneous conditions.The methods and results of this paper can be applied in the PBL parameterization of atmospheric models and some problems concerning in similarity functions.