Fatih peninsula is most important historic area in Istanbul. There are a lot of historical building, made of different building stones, in this area. The most important used building stone is historic Marmara Marble in Fatih area. Marmara marbles having different colors and textures have been quarried in the Marmara Island. This island is one of the oldest major block marble production and processing center in the world. Marmara Marbles were used in many prominent historical buildings and monuments. These marbles were subjected to environmental factors such as water, gas, wind, human and animal activity. The aim of this paper is to determine how these environmental factors effect the weathering of Marmara Marble. In order to identify the weathering characteristics of marbles, petrographic, mineralogic and pyhsico-mechanical properties were carried out. Then, these properties of weathered marbles were also correlated with unweathered marbles. According to the results obtained, weathering of Marmara Marbles were effected by mineral sizes, mineral compositions, pyhsico-mechanical properties of related marbles and cutting and usage styles at the marble productions.