[en] A high burnup UO_2 fuel pellet has been developed by dopant addition. The purpose of adding a small amount Cr_2O_3, MgO or V_2O_5 dopant below 1% weight into UO_2 matrix is to obtain better characteristic of UO_2 pellet with coarser grains and higher density. In large grain microstructure of UO_2 pellet, as the mean value of gas diffusion free path increases, the amount of fission gas released from the pellet will be suppressed, and the fuel burn-up can be increased. The fabrication of doped-UO_2 pellets was done by compacting a mixture of UO_2–dopant powder and sintering at a temperature of 1750 °C with holding time of 4 hours in hydrogen atmosphere.Characterization of UO–dopant pellet involves visual examination, dimensional and density measurement, and ceramography test to study the effect of dopant addition on density and grain size. In this research, the determination of the specific amount of dopant into UO_2 matrix is technically important for the acquisition of large grains microstructure to meet the density requirements in order to improve the reliability of high burn-up UO_2 fuel. (author)