Abstract: XML stream management system fits a large class of new applications such as publishsubscribe system, network monitoring systems, and the extensible markup language has become the de-facto standard for data representation and exchange of Web data. Therefore, there have been a hot spot in the area of data steam research recently. Different from traditional XML database management systems, an XML stream system aims to provide fast, on-the-fly matching of XML-encoded data to user’s query. It usually involves handling the XML stream coming online at any moment and any order, and requiring timely response without incurring more memory cost. Because that XML stream is nested and recursive and user’s interests are represented by XML query languages such as XQuery or XPath, XML stream management system is very different from relational data stream (i.e. tuple based stream) system. In this paper, a comprehensive overview over researches relevant for XML stream management system is presented, the characteristics of XML stream management are pointed out; typical XML stream management systems are compared, existing approaches for processing XML stream are discussed and analyzed including the approaches based on automaton, index and sequence; optimizing techniques for processing XML streams are described. Also, the further researches are pointed out.