Distribution maps of sedimentary facies can be obtained by studying seismic facies in a large research area wherea few wells were drilled. Through seismic and geological demarcation to two typical wells, Well GS-1 and Well YS-104, in central Sichuan Basin, the seismic response models are established for different sedimentary facies in Middle Triassic Leikoupo43 Submember, such as gypsum lagoon, dolomite tidal flat and grainstone shoal facies. On the base of geological demarcation, waveform classification technology are utilized to divide different seismic facies to restore the sedimentary paleo-environment and the distribution maps of grainstone shoal and dolostone tidal flat facies are delineated, which are just the areas of favorable reservoirs. The study result shows that the area from Longgang, Yingshan, Nanchong to Pengxi is located in the favorable sedimentary zones of grainstone shoal and dolostone tidal flat facies where reservoirs are developing since they were affected by karstification near Leikoupo43 Submember denudation border so that they should be the important area of exploration target in central Sichuan Basin.