The Potala Palace has been struck by lightning several times since its establishment. In order to reduce the great losses caused by lightning induced fires, it is necessary to analyze lightningcaused fires scientifically to minimize possible risk. In order to comprehensively analyze the entire process of fires caused by lightning strikes on the Potala Palace, the “fault tree” method were used to analyze multiple causes and processes of fire caused by lightning strikes. The minimal cut sets, the minimal path sets and structure importance of the essential event are given and discussed. Finally, lightning activity regularity in Lhasa area was also analyzed. The results show that there are 308 possible ways to cause fires. Prevention of fires induced by lightning strikes in the Potala Palace is a sophisticated project. The key is to improve defense ability against lightning, such as to eliminate hidden troubles, to install surge protection devices and to practice equipotential bonding.