The interaction between water and cellulose has been studied by deuterium NMR and water sorption isotherm measurements for a bleached kraft pulp and an unbleached liner board pulp beaten to various degrees. Measurements of 2H quadrupole splittings, spin lattice relaxation rates and half height line width shave been carried out at different relative humidities. Furthermore, the spin-lattice relaxation rates at 86%relative humidity were measured in the frequency range 2-62 MHz for the bleached kraft pulp, unbleached liner board pulp and for a microfibrillated cellulose sample. The relaxation rates show a strong dependence on the resonance frequency. The reorientation of the water molecules adsorbed on fibers can be described by two corrletion times ofthe order of 10 ns and 50ps respectively. Analysis of the experimental data does not show any effects of beating on the cellulose water interaction strength. All observations made can be explained by morphological changes of the fibers.