This dissertation aims at studying the German Modern Architecture, the social, political and economical conditions in which it was developed, its theoretical background and its participations in the Modern Movement. The period of time studied in this paper is the first thirty years of the 20th century up to the moment when the Nazis got the power over Germany in 1933. For sixty years, Germany went through wars and other important political changes. The country was unified in 1870 and after the First World War it became a Democratic Republic in 1918. Then, in 1933, it became a Dictatorship with the Nazi government. The First World War affected all Europe and mainly the defeated Germany establishing a boundary in the architectonic production. Besides the political considerations, this moment shows meaningful changes in science and technology which influenced the economy, the industry, the work relations, the family, the human life - individual and collective, the city, the daily objects - both household objects and also the house itself. The professionals of this time had to deal with a set of conditions which would determine the world from then on. These years where expressive in Modern Architecture, not only for the new ideas, but also for the practical attitudes in relation to the contemporary problems.