The growing and melting of crystal nuclei in liquid Cu are investigated by molecular dynamics simulation. The critical undercooling is proportional to the reciprocle of the nanoparticle radius. The Gibbs-Thomson coefficient of Cu is 1.12× 10-7 K·m. Then the crystal-melt interfacial free energy of Cu is 0.146 J/m2 estimated from the Gibbs-Thomson coefficient, and the Turnbull coefficient of Cu is 0.416. All the values by simulation are consistent with the experimental results of Turnbull.