Abstract: Testing for Web applications has challenges on its special aspects. Compared with design and development, relatively little work on testing has been done so far. In this paper, the factors influencing testing for Web applications are analyzed from such cases as its architecture, techniques, elements of its composition, running environment, running mechanism, design process and development process. Main aspects for Web applications testing in design, development, running and evolution steps are summarized. Dynamic testing and static testing are summarized also. Crucial researches from these aspects such as hyperlink testing, black-box testing and white-box testing for components, Web services testing, Web services composition testing and performance testing are surveyed. These problems include object-oriented model and unify Markov model for hyperlink testing, data flow testing and control flow testing for white-box testing, data composition testing for black-box testing, testing for Web services, Web services group, protocol, Web services composition, workload modeling and approaches of creating effective user session data sets for performance testing. Localizations of some methods are pointed out. From model-driven testing, agent-based testing, Web services testing and testing for service-oriented architecture, performance testing, the trends of future research for Web applications testing are also discussed.