Langmuir and Langmuir-Blodgett (LB) films of a newly synthesized side-chain liquid-crystalline polymer (PSLC) and its blend with arachidic acid (AA) have been investigated by means of surface pressure-area isotherms, hysteresis curves, X-ray diffraction, and polarized IR and W-Vis spectroscopies. The results show that AA matrices can enhance monolayer stability and improve the packing of side chains in the film, At high surface pressure, the mixed monolayer undergoes a phase transition from an ordered liquid condensed to a solidlike phase, corresponding to the formation of aggregates or crystallites. Two types LB films (Y and X) can be obtained on the hydrophobic substrates under the condition of different deposition pressures and AA’s proportion. A detailed analysis of the IR dichroism suggests that the axis of the all-trans hydrocarbon chains of AA or spacers in the side chain is less tilted to the surface normal for larger AA’s proportion and the axis of the aromatic Schiff base chromophore is nearly perpendicular to the substrate plane. The hypsoshift of UV-Vis absorption in the film compared with the spectrum in solution indicates that H aggregates form between the chromophore.