Magnetic properties of the ribbons with thicknesses up to 150 mum prepared by single roller melt spinning method, of nominal compositions Nd50Fe40Si10-xAlx (x = 0-10), were investigated. The large values of the intrinsic coercive force up to 350 kA/m, measured at room temperature, as well as the observed anisotropy both in magnetization and coercive force can be explain by the existence of randomly distributed ferromagnetic clusters coupled between them by magnetic exchange interactions through the amorphous matrix. The differences between M-ZFC and M-FC curves as well as the pronounced cusps that appear on the M-ZFC curves at low fields indicate the coexistence of ferromagnetic and spin-glass-like behavior at room temperature.