Abstract Molecular dynamics simulation were used to study the variations of atom radial density distribution profilesρ(r) and internal energy per atom with temperatures for Cun(n=531,603,683) clusters. The studied cluster could be divided into four parts of surface layer and approximate surface layer, etc. according to the calculations ofρ(r). The simulated results show that parts of Cu603 cluster surface layer have been found in the state of disorder, while the rest of the cluster surface layer remains orderly when the temperature is around 770K. The coexistence of order and disorder has been lasting until the temperature of 1000K. The atomic structure of approximate surface layer and inner layer keeps in order as a whole between the temperature of 770K and 1000K. After variation of internal energy per atom with temperature undergo the shape of the letter N during 1000K-1100K, the atomic structure of individual parts of cluster has changed into disorderly at 1080K, but the radial direction of cluster appears layered distribution. The layered distribution of cluster disappears till the temperature of 1500K.
