Abstract: A new encoding scheme named SDUE was proposed, which broke down the node location information for the purpose of avoiding to record redundant information and furthermore it reduced storages space of XML data.Besides,it also supported the updating of XML data. As for the query aspect, the SDUE saved the node path of XML data so as to avoid structural join and then improve the query efficiently. The experimental results indicated that, as compared with other encoding scheme, SDUE had a better performance in the utilization of storage space, updating efficiency and query speed