The present book is an attempt to bring all theories of geography in one book for easy reading of teachers and students. Many divisions in geography has many theories. Readers should take effort to collect the theories from all books. All divisions has certain theories. There are so many theories in physical geography as well as human geography. A simple idea makes it convenient to read the theories in one book. First, we selected the certain theories as follows: Theory of continental drift, The theory of Isostasy, Von Thunens location theory, Crop combination method, The central place theory, Internal structure of city, The rank size rule, The social area analysis method, Losch's theory of economics of location, Walter Isard's theory, Alfred Weber's theory of least cost location, Demographic transition theory, Malthusian Theory of population- Criticism and applicability and Growth pole theory. Like this, there are 14 theories collected and compiled in this book as first volume. The theories collected from both physical geography and human geography. These theories are very important for those who are preparing for UPSC, should go through the theories.