随着传感器网络、RFID等感知技术的应用推广，越来越多的不确定性数据需要被管理和应用，而半结构化数据XML能够很好的对不确定性数据进行表达，因此不确定XML数据库成为数据库领域的热点研究问题。查询处理技术是不确定XML数据管理的核心。不确定XML数据库在传统半结构化数据库的基础上引入了概率来表达不确定性，传统技术不能很好的解决概率带来的新问题，大量的概率信息为数据存储、索引建立和查询处理提出了新的问题和挑战。在新的应用不断发展的背景下，不确定XML数据的复杂查询处理有待进一步深入研究。本项目将研究概率XML数据查询处理的关键技术，提出适应于新应用的通用不确定XML数据模型，设计概率XML文档的编码和存储策略，针对几种复杂查询类型，设计实现查询算法，并构建索引提高查询效率。本项目能解决不确定XML数据的查询处理问题，进一步拓宽不确定数据的实际应用，具有重要的理论意义与实际应用价值。

With the wild application of sensor network and RFID, more and more uncertain data need to be managed and applied. The XML which is a kind of semi-structured data naturally express the uncertainty of uncertain data, therefore uncertain XML database has become the hot topic in database research area. The query processing is the core part of uncertain XML data management. Uncertain XML database is based on the traditional XML database technology, while the addition information is the probabilistic values. The new problem brought by probabilistic values can not be solved by traditional techniques, including storage, index and query processing. Therefore it is a new challenge. With the development of new applications, the researches on uncertain XML data need to be done eagerly. In this project, we study the key techniques of query processing on probabilistic XML data, and we propose new data model for general cases, and design the encoding and storage schemes. To solve the complicated query types, we design the query algorithms and build the index to increase the efficiency. We believe that our project can solve the problems of query processing in uncertain XML database. Also we can apply more uncertain data in the practical applications. The project has values of both theory and practical applications.