My Master Thesis is about the influence of social media on the customers behavior while buying a car. The role of social media for the automotive industry is becoming more and more important. The car manufacturers use social media to create connections with the customers. In Master Thesis I examined the changes of decision behavior and analyzed it with the help of survey. The aim of the survey was to find out what kind of influence does the social network has on the potential customers. Besides I developed and described the full process of buying a car online. Though there is no opportunity to buy a car online todey, the idea of realizing the online process like that is becomnig even more important and interesting with every day.