A fundamental problem in XML data handling is hierarchical data sorting. This paper presents an energyefficient sorting algorithm called EEXPSort for XML document. It exploits multi-core CPU to parallelize the executions of the mutually independent tasks generated by scanning the XML document; For energy-efficiency, it employs data compression, single temporary-file storage and avoidance of tree-matching to effectively reduce disk IOs and CPU process. Extensive experiments on XML documents with different characteristics show that EEXPSort outperforms the existing quickest XML sorting schemes HERMES significantly in energy-efficiency and performance.