A　depth-first　search　(DFS)　algorithm　requires　much　less　memory　than　breadth-first　search　(BFS)　one.　However,　the　former　doesn＇t　guarantee　to　find　the　shortest　path　in　the　VLSI　(Very　Large　Integration　Circuits)　wire　routing　when　the　latter　does.　To　remedy　the　shortcoming　of　DFS,　this　paper　attempts　to　improve　the　DFS　algorithm　for　VLSI　wire　routing　by　introducing　a　method　of　pruning　and　iterative　deepening.　This　method　guarantees　to　find　all　of　the　existing　shortest　paths　with　the　same　length　in　the　VLSI　wire　routing　to　provide　the　wire　routing　designers　more　options　for　optimal　designs.　©　2011　Springer-Verlag.