As the role of the Web as a platform has been extended and HTML5 standard is widespread, many kind of web-based applications have been developed. In many recent applications, two-way communication and server push functionality is required, but HTTP protocol does not support it. As a result, various methods have been proposed and used in order to realize two-way communication on the web. In this paper, these two-way communication methods are briefly introduced and analyzed their strong and weak points in the aspect of implementation, time responsibility, server load and compatibility. Base on the analytical results, it is proposed guidelines for selecting the best method according to the application type and the operating environment.