The present invention relates to a method for deuteration of an inert alkane using activated palladium carbon. The present invention discloses"A method for deuteration of a hydrogen atom of a methyl group or a hydrogen atom bonded to a carbon atom at benzyl position and the other carbon atoms of an alkylene group having not less than 2 carbon atoms, in a compound containing the methyl group or the-alkylene group having not less than 2 carbon atoms, directly bonded to an aromatic ring which may have a substituent, which comprises placing said compound in a deuterated solvent in the presence of activated palladium carbon, under sealed reflux condition".