The purpose of this study is to analyze the 'Sant'Elia Nursery School' constructed in 1937 at Como, Italy. Giuseppe Terragni(1904-1943) is, as it well known, one of the representative architects in the period of Italian rationalism architecture. In particular, his 'Casa del Fascio(1928~1936)' is evaluated as a representative work of this period. The research is based on the original drawings and letters, mostly produced by G. Terragni himself. Through the analyze on the design process, the research tries to reveal Terragni's design method and strategy, especially in the educational facility project. There are at least four deferent phases in the Terragni's design process; in each phase, there are fundamental changes such as a structural grid system, relationships between skin and columns or spatial sequences. Establishment of a new guideline on the educational facility in 1925 is also an another important issue. There was a political need, during the period of Mussolini's regime, to find a model of educational facilities. So, this project reflects not only the Terragni's design process but also the good example of educational facility in the early Twenty Century in Europe.