Thanks to the technical innovation and new demands of modern society, great changes have taken place in the field of French architecture in the 20th century, especially after World War II. Some pioneers tried to find new ways of building to replace the classical tradition. However, the authorities who lead the opinions of the public clung to their preference of traditional architecture for a long time. Even so, some state buildings in modern style began to emerge in France in the 1950s. Many important public buildings constructed in the period from 1940 to 1960 and their building conditions were studied and the result shows that the shift of French state patronage played an important role in the modernization process. This change resulted from various factors, both internal and external. The event was vital for the French mainstream architecture to keep pace with the times.