Histidine is an important and versatile amino acid residue that plays a variety of structural and functional roles in proteins.Although the Raman bands of histidine are generally weak, histidine in the N-deuterated cationic form with imidazole N π -D and N τ -D bonds (N-deuterated histidinium) gives two strong Raman bands assignable to the C 4 C 5 stretch (ν C C ) and the N π -C 2 -N τ symmetric stretch (ν NCN ) of the imidazole ring. We examined the Raman spectra of N-deuterated histidinium in 12 crystals with known structures. The observed ν C C and ν NCN wavenumbers were analyzed to find empirical correlations with the conformation and hydrogen bonding. The effect of conformation on the vibrational wavenumber was expressed as a threefold cosine function of the C α -C β -C 4 C 5 torsional angle. The effect of hydrogen bonding at N π or N τ was assumed to be proportional to the inverse sixth power of the distance between the hydrogen and acceptor atoms. Multiple linear regression analysis clearly shows that the conformational effect on the vibrational wavenumber is comparable for ν C C and ν NCN . The hydrogen bond at N π weakly lowers the ν C C wavenumber and substantially raises the ν NCN wavenumber. On the other hand, the hydrogen bond at N τ strongly raises the ν C C wavenumber but does not affect the ν NCN wavenumber. These empirical correlations may be useful in Raman spectral analysis of the conformation and hydrogen bonding states of histidine residues in proteins.