Magnetic metals deposited on graphene hold the key to applications in spintronics. We here present the results of Fe islands grown on graphene/SiC(0001) by molecular beam epitaxy, which are investigated by scanning tunneling microscope. The two types of islands distinguished by flat or round top can be revealed, indicating a bimodal growth of Fe. The atomic structures on the top surfaces of flat islands are also clearly resolved. Our results may improve the understanding of the mechanisms of metals deposited on graphene and pave a way for future spintronic applications of Fe/graphene system.