The binary phase diagram of the neodymium-copper system has been determined by means of X-ray powder diffraction, differential, thermal analysis (DTA) and metallographic methoa.In this system there exist five intermetallic compounds: NdCu, NdCu2, NdCu4, NdCu5 and NdCu6. The intermetallic compounds NdCu2 and NdCu6 melt congruently at 830℃ and 962℃, and the intermetallic compounds NdCu, NdCu4 and NdCu5 are formed by peritectic reactions at 602℃, 853℃ and 916℃, respectively. Three eutectic reactions occur: at 33 at% Cu and 478℃, 74 at% Cu and 760℃, 91 at% Cu and 874℃. Neither Nd in Cu nor Cu in Nd shows any detectable solid solubility. The solid solubility between intermetallic compounds is undetectable.