Rare earth yttria (Y2O3) reinforced polystyrene composites were prepared by melt blending process. Mechanical properties, wear resistance of the PS/Y2O3 composites were characterized in contrast to neat PS. The improvement of the mechanical properties and wear resistance was attributed to the reinforcing effect of Y2O3 powder. Well distribution of Y2O3 powder in the PS matrix and good interfacial bonding were achieved by pretreated of Y2O3 using titanate coupling and dispersant followed by calcinations process. Results indicated that both of the Y2O3 powder pretreatment process and melt blending process have significant effects on the composite properties. When the Y2O3 content were 2.8wt%, the modify effect to PS was optimal. When the Y2O3 calcined at 900°C was used, the impact of the composites were best, other performance improvements have also been good. When the Y2O3 content of 1.4wt%, the wear resistance of the composites were best.