A method for supporting UI development of an application in a graphical user interface environment is provided. The method includes steps of: (a) a server, if an intention of a user to start editing an action which is a set of UI changes is detected through GUI environment, acquiring a previous state of the UI model, wherein the previous state is a state before editing the action; and (b) the server, if an intention of the user to finish editing the action is detected through the GUI environment, comparing a changed state of the UI model with the previous state thereof to acquire a comparison result, where information on the action having been completely edited is reflected on the previous state of the UI model to acquire the changed state thereof; and recording the information on the action having been completely edited by referring to the comparison result.