Colin Rowe was an important historian, theorist and critic in Modern architecture. His significance in Modern architectural history lies in not only historiography which has changed our view of Modernism but deep theoretical involvement in practice. This study is a critical review and analysis on his formalist approach in Architecture. With a view that his position of formalist has indispensible relationship with liberalism from K. Popper's critical rationalism, this study try to show how his philosophical background has an influence upon his way of seeing architecture, history, form, urbanism, and meaning, etc. And this study also try to explain why the principle of architecture as an autonomous discipline which is the main point of view in Rowe's criticism has been so successful and influential. This study also explain what is the possibility and limitation of Rowe's formalist approach and way of reading buildings. His intelligent way of formal analysis can give us new understandings of how the form generates and the process of design goes on. Furthermore it guide us a new horizon of architecture as a language game. Since his early writings showed both side of formalist approach in architecture and it didn't changed a lot. We can understand his 'Collage City' was a his final answer to his formalist way of making architecture and urbanism. we can estemate it as a utopia without utopianism and an ideology without ideological color.