6LoWPAN　is　a　new　protocol　that　enables　IPv6　to　be　used　in　wireless　sensor　networks.　However,　the　hierarchical　routing　over　6LoWPAN　(HiLOW)　proposed　by　the　IETF　6LoWPAN　Working　Group　may　be　too　simplified　due　to　the　use　of　dynamically　assigned　16-bit　short　addresses　in　6LoWPAN　to　establish　a　hierarchical　tree　between　parent　and　children　nodes　for　packet　transmission　since　performance　would　degrade　when　a　node　tries　to　communicate　with　another　nearby　node　over　several　hops.　In　this　paper,　we　propose　a　scheme　to　improve　the　efficiency　of　routing　for　the　existing　hierarchical　routing　algorithm　and　perform　performance　analysis　with　an　experiment　to　show　the　improvement.　©　2011　IEEE.