By reacting (-Ag-O-) strings on Ag(110) with Cu atoms at room temperature, (-Cu-O-) strings were grown on the Ag(110) surface. The (-Cu-O-) chains grow along the [110] direction and are ordered in a p2mg(2x2) structure on the Ag(110) surface. When a p2mg(2x2)(-Cu-O-)/Ag(110) surface was heated for several minutes at 570 g, the (-Cu-O-) strings were rearranged to a p(1x3) structure and the (-Cu-O-) strings underwent the preferential decomposition along the phase boundary of the p(1x3) domains. The decomposition of the (-Cu-O-) strings yielded uniform size (Cu)(6) cluster dots (similar to 8 A) along the [1(1) over bar 0] axis on the Ag(110) surface and its reverse reaction, the (Cu)(6)+O-2-->(-Cu-O-) string, took place also along the [1(1) over bar 0] axis at room temperature.