Abstract: The preparation process of irradiation target for ~(99)Mo--~(99m)Tc production fromthe Mg--UO_2 dispersion fuel rod (10% ~(235)U) is described. The main proceduresinclude clad thinning by alkaline etching, cutting of fuel rod, extrusion bondingthe end cap under pressure, seal welding, quality examination and so on. The targets prepared were irradiated in the swimming--pool light--water reactor.Experiments on radioisotope separation were performed. Results suggest that thetarget is well designed. The characteristics of the target meet the needs for separa-tion. The development of this target provides favorable conditions for experimentalstudies and production of ~(99)Mo--~(99m)Tc radioisotopes.