The ［Co8585Cr1515/Pt］2020 multilayers w ith Pt underlayers were prepared by magnetron sputtering and the effects of sputtering Ar gas pressure on m icrostructure and magnetic properties of ［Co8585Cr1515 /Pt］2020 mul tilayers were studied. The results show that sputtering Ar gas pressure has a gr eat effect on the microstructure, perpendicular magnetic anisotropy and the coer civity of ［Co8585Cr1515/Pt］2020 mul tilayers. For all samples, we have the effective magnetic anisotropy constant K effeff＞0, and all s amples showed perpendicular magnetic anisotropy. With increasing sputtering Ar g as pressure, the perpendicular and in-plane coercivity of the samples increase, but the effective magnetic anisotropy constant decreases. The coercivity of Pt( 20nm)/［(Co8585Cr1515(05nm)/Pt(15nm)］2020 multilayers spu tter-depositied at 16Pa Ar gas pressures is increased to 130kA/m. The Pt( 20nm)/［(Co8585Cr1515(05nm)/Pt(15nm)］ 2020 multilayers display perpendicular magnetic anisotropy and can be used as perpendicular magn etic recording media. The images of atomic force microscopy show that both avera ge grain size and the surface roughness increase with increasing sputtering Ar p ressure, which leads to the enhancement of perpendicular coercivity and the decr ease of effective magnetic anisotropy constant.