Molecular dynamics (MD) computer simulations have been carried out to study the structures, properties and crystal nucleation of nanoparticles with 453 Cu atoms. Structure information was analyzed from the MD simulations, while properties of nanoparticles of Cu 453 , such as melting point, freezing temperature, heat capacity and molar volumes, have been estimated. The face center cubic (FCC) phase and icosahedron (Ih) phase were observed during the quenching process, and nucleation rates of crystallization to FCC crystal of Cu 453 at temperatures of 650, 700, 750, and 800 K were analyzed. Both classical nucleation theory (CNT) and diffuse interface theory (DIT) were used to interpret our observed nucleation rates. The free energy and diffuse interface thickness between the liquid and the FCC crystal phases were estimated by the CNT and DIT respectively, and the results show that the DIT does not work properly to the system.