XML is merging as the main standard of presentation and exchange on the Internet. Various XML query languages are proposed. As a ubiquitous part of those XML query languages, path expression poses a new challenge for efficient XML query processing in database systems. In this paper, we present a new index structure, Structural Map, for efficient evaluation of path expression queries. Structural Map can be used to support path-indices as well as value-indices in an integrated manner. It is powerful to handle not only simple path expressions but also the branching path expressions and path expressions with predicates efficiently. Performance study shows the Structural Map can improve the performance of XML path expression processing significantly.