On the basis of the rotational Brownian motion equation, we have analyzed the dielectric relaxation phenomena in Langmuir films, assuming that the orientational distribution of the constituent rod-like polar molecules is ruled by Boltzmann statistics. In this report, an equivalent circuit model representing the transient relaxation process by monolayer compression is presented, and the dielectric relaxation time τ of the monolayers is obtained in a generalized form. Finally, we examine the generation of Maxwell displacement current (MDC) across a 4-cyano-4'-8-alkyl-biphenyl (8CB) Langmuir film at the onset of the polar orientational phase by monolayer compression on the basis of the analysis developed here.