La_0.6Pr_0.4Fe_11.4Si_1.6B_0.2 alloy of kilogram grade was produced by induction melting method with industrial raw materials, then the annealed alloy was hydrogenated to increase its Curie temperature to around room temperature. The microstructure of the alloy was examined after annealing at 1373-1473 K for different times. The Curie temperature of the alloy annealed at 1473 K for 30 h is 202 K and the maximum magnetic entropy changes are 8.1-8.6 J/kg.K under a magnetic change of 1.5 T. The Curie temperature of the alloy was increased to 320 K by hydrogenating at 553 K and 0.13 MPa H₂ pressure for 5 h, and the maximum magnetic entropy changes of 7.7-8.0 J/kg.K were also obtained.