It is becoming possible to interpret the adsorption characteristic in a molecule level rationally, and to predict the macroscopic characteristic such as adsorption isotherms in recent years. However, information on force field parameters and charges are often inadequate, even in systems where the structure is well known. From the environmental point of view, the adsorption of chlorinated hydrocarbons and ethanol by the use of zeolites may have some potential utilities in ground water or soil remediation and other areas. The simulation result indicated a big value compared with the experiment value. But by comparing an experiment result with a molecular simulation result, the validity of forcefield parameters and zeolite model was examined. Hereafter, it is thought that those further comparative studies are necessary.