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 tau 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.