Ample evidence from physicochemical experiments suggests that bituminous coals can be described as highly crosslinked and entangled networks of macromolecular chains of irregular structure. Theoretically these structures can be analyzed by statistical mechanical models considering non‐Gaussian distribution of the macro‐molecular chains along with departure from the Flory theories of crosslinked macromolecules. The models of Kovac (1978) and Peppas and Lucht (1979) have been developed in order to describe non‐extractable coal matrices and their behavior during swelling in appropriate swelling agents. The molecular weight between cross‐links Mcand the crosslinking density &rgr;xcan be determined for various solvents and equilibrium swelling ratios. Few experimental data are available to which these models can be applied. Thus, in view of these new theoretical models, experimental research must be directed towards the reexamination of extraction and swelling behavior of bituminous coals. Some of the important parameters to be determined for characterization of the physical structure of coals include the thermodynamic interaction parameter &khgr;, the crosslinking parameters Mcand &rgr;xand the molecular weight distribution of the extractable coal portion.