The structure of coal is not a covalently cross-linked network, but rather, is represented by the physically associated model. Furthermore, the solvent swelling of coal is dependent on coal concentrations. The swelling kinetics of coal in slurry is, therefore, different from swelling kinetics during the sorption process of cross-linked macromolecules. By applying theoretical and experimental analyses, this paper explores the reevaluation of swelling kinetics of coal in slurry. Conventional analysis may lead to erroneous parameters when based solely on the premise of using the empirical equation derived from the sorption process. For this reason, normalized swelling curves of the first-order process, in addition to Fickian and Case II diffusion, were introduced to analyze swelling kinetics. Analysis consisted of tests under various conditions, where each swelling process adhered to the steps dictated by the first-order process. Interpretation of the results concludes that solvation of intra- and intermolecular complexes is the essential rate-determining step for coal swelling in slurry. This finding counters the concept that solvent diffusion in a coal network is considered the rate-determining step.