With the coming of 3G ages and the high-speed growth of Web resources, there is a trend of rapid development in mobile Internet, making resources accessesible and information obtainable conveniently by using mobile devices. However, in mobile Web search, these are very challenging tasks to geo-tag Web resources, integrated spatial data and Web data seamlessly, and provide valuable and high-relevant information to users. A framework of mobile Web search is proposed in this paper, and the key research techniques in mobile Web search are classified and surveyed according to this framework. Based on the comprehensive comparison and analysis of existing techniques, the suggestions for future research are put forward.