In the contemporary architectural form, there are some tendency that formal building form in the past transforms into informal form. Formalistic form means geometrical shape and form, especially rectangular coordinates. Against the concept, informal form means that it is escape those formal characteristics by using free curve, oblique line, and so on. In the modern times, formal building form is the main form. But after the war, the ideology based on production transforms the modern pure heart. Thus the box building form was used in the city building mainly. The box building form was the mass productional form. Because of these forms, the city view has been uniform standardization and non-personality. But in the processing contemporary architecture, there is the tendency that subjective forms are appeared by architects' instuition. This paper proves that there are some occurrence backgrounds after 1950s' architectural, social consideration and architectural expression characteristics. The conclusion is that non-formalistics, organism, commodity and experimentalism are the expression characteristics, and analyze some buildings.