Abstract: In order to describe in detail thermal and hydrological exchange in soil-vegetation-atmosphere continuum,a simple and universal scheme of vegetation parameterization is established based on the effective specific humidity.It is an isothermal "big leaf" scheme.The scheme is tested using observation data from three experimental stations and the computed sensible heat flux,latent heat flux,net radiation and soil temperature have been compared with the observations,the result shows that this scheme could describe the transfer feature of heat and water successfully.