Abstract：Photochemical reaction of nitrogenous heteraromatic compounds with uracil aldehyde, aromatic aldehydes and ketones, fused polycyclic aromatic hydrocarbons in solid state were investigated and were distinct from that solution. The structures of 19 new compounds synthesized were determined by IR, ^1H NMR, MS and elemental analysis. Theses mixed crystals have been characterized by the powder X-ray diffraction spetra and differential scanning calorimetry curve. The mixed crystals of indole with naphthalene and carbazole with anthracene were found to form molecular compounds. The reaction mechanism was postulated.