Abstract: The dating of formation age of clastic rock is the premise of the division and correlation of sedimentary strata, reasonable reconstruction of prototype basin, better understanding of the regional tectonic evolutions and scientific evaluation of regional resources. According to the principle of " the temperature of sediments or sedimentary rocks increases with increasing burial depth ", the formation age of clastic rock can be determined by the initial burial warming time of thermal history which can be reconstructed by means of apatite fission track (AFT) thermal history simulation. Previous applications of AFT thermal history simulation and the example of sandstone sample of Liupanshan indicate that it is feasible to date the formation age of clastic rock by the simulated thermal evolution history, using clastic samples that experienced burial temperatures of less than the closure temperature in the thermal history simulation of fission track.