The present invention is directed to method and apparatus that enables a web-based client-server application to be used offline that substantially obviate one or more problems due to limitations and disadvantages of the related art. According to one aspect of the present invention, a method for using a web-based client-server application offline, the method comprise: reading a markup file including a list of web resource file and period information; connecting periodically to web server according to the period information; downloading the web resource file included in the markup file form the web server to a cache included in the application.