The magnetic properties and crystallization of amorphous Nd-2(Fe1-xCox
)(23)B-3 alloys were studied. The Curie temperature T-c is found to in
crease monotonously with increasing Co concentration x, while the satu
ration magnetic moment mu(s) shows a monotonous decrease. The crystall
ine phases in crystallized samples were identified by X-ray diffractio
n. When the amorphous alloys were annealed at about 900 K, they crysta
llize to the metastable single-phase compounds of Nd-2(Fe,Co)(23)B-3.