Most prefix-labeling scheme nowadays cannot support XML document updating fully. Based on the comparison of the current prefix-labeling scheme, a novel prefix-labeling was proposed. This scheme does not only efficiently support structure queries, which can rapidly and accurately judge the parent-child, ancestor-descent and sibling relationships between any two nodes of the XML document tree, it also adopts the new labeling rules to avoid an update coding adjustment operation that may bring about when new nodes are inserted, and effectively support update for XML document.