Characterization of the Langmuir-Blodgett (LB) films of polyamic acid tert-amine salts (3a-3c) containing single, double and triple chains, and polyimide (4) was carried out. The LB films obtained from the monolayers for 3b and 3c showed X-ray diffraction peaks, whereas these peaks were not observed for 3a. The d spacings and diffraction intensity of LB films for 3b transferred from the expanded phase increased with time after deposition and increasing deposition pressure, and their values approached those obtained for films transferred from the condensed phase. On the contrary, the LB films for 3c displayed a constant d spacing of 5.4 nm, irrespective of whether they were built up from the expanded phase or from the condensed phase. The thickness of LB films was estimated from X-ray interference, X-ray diffraction methods and observation of micrographs, and the monolayer thicknesses obtained were in fairly good agreement with one another.