To clarify the relation between packing structure and reactivity of monomer molecules in the photoinduced solid-state polymerization, we analyzed crystal structures by X-ray diffraction for a series of dialkyl muconates with various types of side group. Single crystal of diethyl (Z,Z)-muconate (diethyl (Z.Z)-2;4-hexadiendioate) changed into the stereoregular polymer crystal by irradiating visible or ultraviolet light at room temperature. The dicyclohexyl (Z,Z)-muconate and the dibenzyl (Z,Z)-muconate showed the isomerization reactions from (Z,Z) form to (E,E) form. The bisdecyl (Z,Z)-muconate and bis(2,2,2-trichloroethyl) (Z,Z)-muconate changed into amorphous polymers. All the compounds used in this study have the columnar structures. The distance of the butadiene carbon atoms of the neighboring molecules alone the columnar axis was 3.5-6.4 Angstrom; almost no correlation could be found with the reactivity. The tilt angle of molecular axis from the columnar axis was estimated to be 38-78 degrees, which could dot be assumed as a good index to represent the reactivity of monomer molecules. Rather, a set of the distance and the tilting angle seems to be better index, but it could not necessarily explain the difference in the reactivity for all the substances. The free volume or the cavity between molecules is also not a proper measure. The degree of overlap of pi -electron orbitals between the butadiene carbon atoms of the neighboring molecules was found to work as a relatively good measure of their reactivity. The systematic study of the molecular packing geometry for a series of muconate derivatives brought up a very important warning about the conventionally made discussion on the factors governing the solid-state polymerization reaction based on only the interatomic distance, the tilting angle of the molecules, etc.