Abstract: The study on isothermal models of paraffinic hydrocarbon adsorption in underground porous media,which is difficult but of practical and theoretical significance,is the foundation of phase behavior laws,fluid flow and reserves calculation in real gas con-densate reservoir.The content presented in this paper is one part of the subject, which has few research literatures published.
This paper consists of three parts.In the first part,a series of single component and multi-component gas adsorption isother-mal models commonly used in chemical engineering practice are described,which are quite complete.These conventional models range from homogeneous to heterogeneous adsorption system,from ideal condition to real reservoir condition.In the second
part,the properties of porous media in real gas reservoirs,which is of stronger heterogeneity than that in chemical engineering field,have been studied.And in the third part,a new idea to de-velop gas adsorption isothermal models in a real gas reservoir was put forward on the basis of the experimental data of hydro-carbon adsorption from core in order to describe accurately the
adsorption of hydrocarbons in real reservoir porous media.

Key words: reservoir, core, hydrocarbon, adsorption model