Abstract: The structural changes of a binary metal Au24Cu19 cluster containing 24 gold atoms and 19 copper atoms on quenching and continuously cooling procedure were studied by NVT moleculardynamics simulations within the framework based on the embeddedatom method. On the analysis of average potential energy per atom， pair numbers of the main atom bond， and the atom packing structure varying with the temperature， the clusters presented the configuration that the inner part was the copper atoms， coated with the gold atoms and a few of copper atoms with the decrease of the temperature. At the relative high temperature regime， the pair numbers presented highlow vibration changes during the process of quenching， whereas they presented lowhigh vibration changes during the continuously cooling process. At the relative low temperature regime until 400K， the pair numbers were changed synchronously under both cooling conditions.

Key words: alloy, phase transition, molecular dynamics, clusters, surface