An R-T-B system rare earth permanent is provided, which comprises a sintered body comprising: an R.sub.2T.sub.14B phase (wherein R represents one or more rare earth elements (providing that the rare earth elements include Y) and T represents one or more transition metal elements essentially containing Fe, or Fe and Co) as a main phase; and a grain boundary phase containing a higher amount of R than the above main phase, wherein, when Pc (permeance coefficient) is 2, if a total flux is defined as f1 under the application of an effective magnetic field of 240 kA/m (providing that an effective magnetic field=an applied magnetic field-a demagnetizing field, and each value of them is absolute value), if a total flux is defined as f2 under the application of an effective magnetic field of 800 kA/m, and if a total flux is defined as f3 under the application of an effective magnetic field of 2,000 kA/m, a magnetization rate a (=f1/f3.times.100) is 40% or more, and a magnetization rate b (=f2/f3.times.100) is 90% or more.