The magnetic phase transition and magnetic entropy change |ΔSm| of melt-spun La 1−x Nd x Fe 11.5 Si 1.5 (x=0, 0.3, 0.5) ribbons were investigated by measuring the magnetization as a function of temperature. The crystal structure of all annealed ribbons is NaZn 13 -type. The Curie temperature T C of the ribbons increased slightly with the increase of x. A large low-field |ΔSm| is observed in the compounds with x=0 and 0.3, which resulted from a field-induced first-order magnetic phase transition (FOT). For the compound with x=0.5, |ΔSm| reduced sharply and FOT disappeared at the same time. Enhancement of T C and |ΔSm| by Nd substitution suggests that La 1−x Nd x Fe 11.5 Si 1.5 (x=0, 0.3) ribbons have great potential for applications as magnetic refrigerants working in low magnetic fields.