A thorough study of the vibrational spectra of two disaccharides, melibiose and turanose, is presented in this work. The infrared and Raman spectra of these two compounds have been first recorded in the mid infrared range then in the far infrared region (for Raman only). These spectra constitute the main experimental support for the calculations of the modified Urey-Bradley-Shimanouchi force fields of these two disaccharides. Good agreements have been obtained between the observed and calculated frequencies. In a second time, spectra of O-deuterated derivatives have been recorded and used in order to confirm some of the frequency assignments and to test the validity of the obtained force fields.