We have investigated the perpendicular magnetic anisotropy of a [CoSiB t(CosiB)/Pt 14 angstrom](5) multilayer as a function of the CoSiB thickness. We have studied the perpendicular magnetic anisotropy of [Co t(Co)/Pt 15 angstrom](5) and [CoFe t(CoFe)/Pt 10 angstrom](5) multilayers for various thicknesses of Co and Co Fe. Furthermore, we have measured and compared the coercivities and the saturation magnetizations of all samples. In this study, samples were [Co t(Co)/Pt 15 angstrom](5), [CoFe t(CoFe)/Pt 10 angstrom](5); and [CoSiB t(CoSiB) /Pt 14 angstrom](5) with t = 2, 3, 4, and 5 angstrom. The coercivities and the saturation magnetizations were obtained 223.76 Oe and 341.25 emu/cm(3), 395.86 Oe and 286.79 emu/cm(3) and 155.13 Oe and 429.98 emu/cm(3) in CoSiB/Pt, Co/Pt and Co Fe/Pt mutilayers, respectively. The maximum coercivity was obtained 395.86 Oe in the [Co 3 angstrom /Pt 15 angstrom](5) rnultilayer, and the minimum saturation magnetization was 286.79 emu/cm(3) in the [Co 2 angstrom /Pt 15 angstrom](5) multilayer.