Abstract: The polystyrene pellets doped with Cr_2O_3, made by emulsion technique wereprepared. Three different solutions including two water and one oil phases were used forthis process. The W_1 phase (water) was mixed with the O phase (3% Cr_2O_3-PS solu-tion, benzene and dichloromethane mixture as the solvent) to form W_1/O emulsion.The W_1/O phase was poured into 5% PVA aqueous under stirring. Then this processfollowed with other post--treating means: washing and drying. Parameters of the typicalCr_2O_3-PS hollow shells fit the requirement of ICF experiments.