Abstract: Yuanliang Mountain tunnel, one of the longest and deepest buried tunnels in the world, is the stick-point of the planned railway from Chongqing city to Huaihua City in southwest China. It will span 11.068 kilometers and its maximal depth is 780 meters. The tunnel will traverse the Maoba syncline that mainly constructed by limestone. The Karst phenomena are well developed in the middle of the syncline. So there is the great possibility of dash-water during the period of the construction of the tunnel. A mosaic image consisting of three scenes of ETM data was analyzed and interpreted for the Maoba syncline. The distributions of folds and}faults are analyzed using remote sensing ETM data. Based on this information, the mechanics characteristics of neotectonic movements of the faults and Maoba syncline in this area are identified.