These brief remarks concern to the use and the importance of the survey in sight for the analysis and a meditated observation on the modern Brazilian architecture. In September of 1956, a few months after his proclamation, President Juscelino Kubitschek calls for a meeting Niemeyer, announcing: "Oscar, we will build the capital of Brazil. A modern capital. The most beautiful capital of the world." The modern project of Brasilia was the symbol of an age of great changes in the country. Made in three years and seven months on the basis of the pilot plan of Lucio Costa, it still remains the prime example of modern architecture in South America. The buildings examined are of great value, the sites near the Eixo Monumental, the main artery of Brasilia, which form the core of the city. The aim and the purpose of this research are focused on the utility of the survey in sight as a tool for knowledge and understanding of some buildings like the Palacio do Planalto, the Palacio da Alvorada, the Supremo Tribunal Federal, the Museu da Cidade, and finally the complex of the Congresso Nacional.