This paper has been investigated the effectiveness of Web 2.0 technology in virtual universities. Web 2.0 tools refer to the Web-based applications that allow virtual students to collaborate, communicate, and share information in a virtual or online learning environment. The population has been virtual students in developed and developing countries that based on Krejcie and Morgans’ table, 384 students have been selected as sample. The results show that there is relationship between the use of Wikis, Podcasts, Blogs, and Web 2.0 technologies and students achievement in virtual university. Also using the Web 2.0 technology creates changes in communication, learning strategy, teaching methods, and interaction between learners and instructors. In virtual university many Web 2.0 tools contain characteristics of social software that maintain the ability to connect users and allow users to create Web content through collaborative efforts. Wikis, podcasts, and blogs represent social software that allows learner to collaborate by exchanging information through the Internet. Interaction and collaboration encourage learners to construct their knowledge, which remains characteristic of a constructivist approach to learning.