The relaxation properties of single layer and multilayer graphene sheets were investigated using molecular dynamics simulation with REBO and AIREBO bond-order interatomic potential, respectively. The dynamic evolution of graphene sheets during relaxation was analyzed. The simulation shows that the sheets are not perfectly flat after relaxation，but show microscopic wavy corrugations at the sheets edges，but not in other areas. In addition，the waviness at the edges of multilayer graphene sheets is a little less than that of the single layer sheets.