Abstract: Research of architecture heritages requires a harmonious work of multidisciplinary team of specialists dealing with history, art and structural mechanics and materials. It is the three aspects of the research of historical architecture heritages, i.e. architecture history, architecture art and architecture science. Preservation and research are nowadays an essential requirement for the famous monuments, buildings, towers and others. Our society is more and more conscious of this necessity, which involves increasing activities of restoration, and then sometimes also of repair, mechanical strengthening and seismic retrofitting. Many historical buildings have in fact problems of structural strength and stability; the need for research on structural mechanics and materials is definitely growing.Xi'an is a historical and cultural city. Xi'an and Xi'an area served as capital of twelve dynasties, spanning over 1080 years. Many historical buildings of Tang dynasty and Ming dynasty are preserved up to now. Our researches on structural mechanics and materials of historical structures were begun since 1982. It was the need of the repair of some national preservation relics, including the Arrow Tower at North City Gate, Bell Tower at the center of city, City Tower at East City Gate, City Wall in Xi'an etc. These researches also include some brick masonry such as the Big Goose Pagoda and Small Goose Pagoda. The structural mechanics of ancient architecture, mechanical characteristics of ancient soil under foundation and city wall; the influence of caves in and under the Ancient City Wall built at the age of "Game of Four (1966-1976)" on the stability of wall; behavior of "Dougong" and Joggle joint of wooden structure, differential settlements of Arrow Tower and resistance to earthquake of these historical architecture heritages are studied. This paper gives a summary of these researches.