The　concrete　arch　bridge　is　a　natural　and　appropriate　structural　solution,　aesthetically　pleasing　and　easily　integrated　into　the　environment,　especially　in　mountainous　and　island　areas.　However,　construction　difficulty　and　cost　will　increase　with　heavy　self-weight　when　the　span　enlarges.　A　potential　solution　is　to　use　a　composite　box　arch　ring　with　steel　web-concrete　flange.　Taking　Wanzhou　Yangtze　River　Bridge　(the　longest　concrete　arch　bridge　in　the　world　with　a　main　span　of　420　m)　as　a　prototype,　trial　designs　of　a　composite　box　arch　with　steel　webs　(including　corrugated　steel　webs　and　plain　steel　webs)　and　concrete　flanges　were　carried　out.　Comparison　of　quantities　and　structural　behaviors　of　the　prototype　concrete　arch　with　the　two　trial　designed　composite　arch　was　presented.　It　is　shown　that　the　self-weight　of　the　composite　arch　can　reduce　about　28%　and　the　structures　can　meet　the　design　requirements,　therefore　it　is　possible　to　use　the　two　composite　arches　in　long　span　arch　bridges.　©　2010　Higher　Education　Press　and　Springer-Verlag　Berlin　Heidelberg.