Abstract: Based on the non-uniform constitution of coal, a methamatical model has been developed to simulate coal liquefaction. The model considers the overall liquefaction to be achieved in two stages. Both stages consist of a series of paralled irreversible reactions, of which the activation energies obey normal distribution. The model gives rational expression to the phenomenen that some parts of coal are easy to liquefy but the others are not. It also sucessfully predicts the increase of apparent activation energies with coal conversion. The theoretical values derived from this model show good agreement with our experimental results, as well as with the data reported in the literature.