This undergraduate thesis tries to examine several impacts caused by Brexit on Britain political economy which this political decision taken by Britain is such a new condition of a country wish to leave from European Union membership. Since the European Union is regulated single market which give every members mobility of goods, services, capital and people freely to move around its territory and as the member of European Union, both of Britain and EU are interdependence in political economic means. Thus, the decision of Britain to leave will create several impacts to the condition of Britain itself both of politically and economically