Principles of development of graphic user interface are considered in the article. Possibility of creation is described by comfortable and clear to the user of model of co-operating with software without the necessity of study of some special language. The authors, based on the analysis of development of user interface, pointed out a problem on bearableness of software on other operating systems, because a graphic interface essentially depends on the possibilities given by the operating system for his creation. The article is sanctified to the analysis of principles of creation of user interface. An attempt to identify factors that are a prerequisite for creating an effective user interface model was made.