For improving the hydrophilicity and cell compatibility of PLA, electron beam was used to induce grafting of NVP on PLA in different conditions (irradiation dose, ethylic acid concentration). PLA-g-PVP copolymers with different graft ratio were attained. The degradation behaviors of the materials were investigated by mass loss, molecule weight loss and water intake measurement. The experimental results showed that the hydrophilicity and degradation rate of the grafted materials were improved with the increase of the graft ratio. Compared with PLA, the PLA-g-PVP copolymers showed higher hydrophilicity and faster degradation rate due to the incorporation of hydrophilic PVP units. These PLA-g-PVP copolymers can be expected to apply in tissue engineering for their great potentials in having good cell affinity to be cell scaffold materials.