The vibrational spectra of beta-D-fructopyranose crystals have been recorded in the 4000-400 cm(-1) region using the infrared and in the 4000-20 cm(-1) region using the Raman. These spectra are used as an experimental basis in order to establish a force field for the beta-D-fructopyranose molecule in the crystalline state through a normal co-ordinates analysis. For this purpose, a modified Urey-Bradley-Shimanoushi force field was combined with an intermolecular potential energy function that includes the van-der-Walls interactions, the electrostatic terms, and an explicit hydrogen bond function. The force field parameters are derived from those of beta-D-glucose and are fitted so as to obtain a good agreement between the calculated and the observed frequencies. The results obtained demonstrate the reliability and the transferability of the set of parameters constituting the initial force field. The fitted force field reproduces the experimental spectra to a marked degree of accuracy.