I.r. and Raman spectra of acetamide CH₃CONH₂ and its emicloridrate (CH₃CONH₂)₂·HCl are reported and discussed. I.r. spectra of (CH₃CONH₂)₂·HCl shows a large and strong absorption about 850 cm^-1, which is absent in the i.r. spectrum of CH₃CONH₂ and in the Raman spectra of CH₃CONH₂ and (CH₃CONH₂)₂·HCl. Such a band can be attributed to an antisymmetric stretching vibration of (O--H--O)⁺ strong symmetric hydrogen bond between the carbonyl groups $\rangle C = O- -H^{+}- -O = C\langle$ of the (CH₃CONH₂)₂·H⁺ ion, vibration which is allowed in i.r. but not in Raman. Such a hypothesis agrees with a partial X-ray study of literature on (CH₃CONH₂)₂·HCl in which is suggested a strong and symmetric hydrogen bonding $\rangle C = O- -H^{+}- -O = C\langle$ with $O \cdots O$ bond length of 2,4 Å. It agrees also with the behaviour of $\delta OH$ deformation vibration and with that of symmetric stretching $\nu O--H--O$ vibration. Tentatively, an attribution of the i.r. and Raman spectra of (CH₃CONH₂)₂·HCl is given in relation to that of CH₃CONH₂, considering the symmetry of the C_i, point group for the (CH₃CONH₂)₂·H⁺ ion and the coupling of the vibrations through the (O--H--O)⁺ strong hydrogen bond.