This study aims to analyze the users' form of interaction and problems in terms of interface design considering the people's constant interaction with mobile devices which has an important place in their daily life. For this purpose, the location of interface design elements and the changes caused in this development process of mobile communication technology are addressed. Because it is directly associated with the topics, required literature reviews has been done, descriptions and opinions related to the interface design have been given place. In addition to this, the notion of usability, interface usability, user-oriented interface design and the importance interface in the human-computer interaction are tried to be explained. Due to this the most widely used operating systems of Android and IOS, interface design of these operating systems it was analyzed by considering the basic graphic design principles. In order to measure the usability of these interfaces, one of interrogation methods based on information collected from the focus groups. At the end of the study, results of design analysis of the participants were compared and situation evaluation has been done.