The nucleation and growth of metal nanoclusters on a Si (111)-7x7 reconstructed surface were studied using a kinetic Monte Carlo simulation. The main atomistic processes included in the model were the diffusion of adatoms between half-unit cells of the 7x7 surface, and aggregation and decay of clusters within the half-unit cells. Considering the structural difference between faulted and unfaulted half-cells, the model introduced an asymmetrical adatom aggregation mechanism by setting different effective binding energies for clusters in the two different types of half-cells. This gave rise to preferential occupation of clusters for the faulted half-cells. Simulation of the model produced growth-mode transitions from a hit and stick regime at low temperatures to a self-organized growth regime at high temperatures. A comparison with relevant growth experiments demonstrated good qualitative agreement. Metal-Cluster Growth with Asymmetric Diffusion and Reversible Aggregation on Si (111) 7x7. D.Wang, H.Zhu, L.Wang: Journal of Applied Physics, 2008, 103[2], 024306