Temperature dependences of magnetic susceptibility within the range of 300 to 1200K were plotted and analyzed with the use of Faraday method for initially ordered solid solutions Pd3Fe1-xMnx (x= 0.15 - 1.00). Computer processing of experimental data made it possible to determine main parameters of alloy magnetic state and their concentration dependences for atomically ordered and disordered states. Within the framework of Heisenberg crystal model an evaluation of critical concentration was made at which magnetic phase transition occurred in ordered alloys. In the vicinity of this concentration a band constituent of magnetic susceptibility was shown to reach its peak.