In recent years, green building is booming, and with increasing public institution buildings "aging", energy consumption increased year by year, green retrofitting is imperative. Research selected 10 typical public institution buildings in different climatic regions in China to carry out research on green retrofitting projects, according to the basic situation before the retrofitting, the types and the retrofitting technology, the effect after the retrofitting and the existing problems, the author analyzes the present situation, characteristics and existing problems of green retrofitting of public institution buildings in China. Which will provide reference for the continuous improvement of the green building evaluation system and the technical system of existing buildings green retrofitting in public institution. Typical public buildings green retrofitting projects as shown.