The purpose of this study is to investigate and evaluate the effects of a Web-based Virtual Class applied to graduate level Nursing Jnformatics. TopClass, a Virtual Class Platform provided by the Virtual University at Seoul National University, was used in this study to implement a web-base learning environment. Lecture and discussion strategies were used for the class. Additional functions including e-mail, offline chatting, BBS, quiz pooi, online exam, image upload and new message alarm were used to facilitate the class operation. Twenty-one graduate students participated in virtual class and received virtual lecture on the Internet. They were asked to rate their knowledge, actual use and capability of computer and Internet and write their expectation and feedback on the course at the beginning and at the end of the course. There were significant differences in knowledge, actual use, and capability of computer and Internet between pre and post. Students indicated that repeat learning beyond time and space, improvement of communication between students and professor, immediate professor' s feedback and improvement of understanding and ability to use computer and Internet and computer, were addressed as useful aspects of virtual class. Lack of active participation in discussion session, the need to have a group work and heavy load of assignment were pointed out as dissatisfaction.