Abstract: Uncertain data has already widely existed in many practical applications recently, such as sensor networks, RFID networks, locationbased services, mobile object management, online shopping, and market surveillance. Uncertain skyline query, as an important aspect of uncertain data management, has received considerable attention in database and network computing fields recently, due to its importance in many practical applications, such as decision making, market analysis, and environment surveillance. Firstly, many existing definitions of skyline queries on various uncertain data, including the definitions on the discrete and continuous probability distribution model and incomplete data, have been extensively presented. Secondly, based on the analysis of the characteristics of skyline queries, various existing centralized and distributed skyline queries approaches are addressed, especially for the principles, as well as the advantages and disadvantages of the approaches. Thirdly, the skyline query definition over uncertain data streams is introduced and the existing studies on skyline queries over uncertain data streams are surveyed. Finally, based on the latest research work, some directions of the future research of uncertain skyline queries are outlined.