The cloudtoground flash data of Chongqing from 2006 to 2008 from the lightning location system (ADTD) is used to analyze the regularity of lightning activities of the straddletype monorail system (No.2) by the linecorridor method. A vulnerability analysis is made, with the lightning parameters including the number of lightning strokes, the number of thunderstorm days per year, cloudtoground flash density, the distribution of lightning current magnitudes, and the distribution of lightning locations. The results indicate that the section from Linjiangmen to Fotuguan is the area that has higher occurrence probability of critical lightning current, relatively larger mean ground flash density, and shorter average distance from the stations, which is easy to be attacked by lightning strokes and is considered as the key area of lightning protection because it is located along the riverside and has steep topography.