Abstract: The Mesozoic strata of well Lunnan No. 1 contained abundant fossils such as sporo pollen, ostracods, triopsand conchostracans and so on. These fossis proved that the lower trlassic, the middle and upper triassic strata,Yangxia Formation of lower Jurasslc, Kapushaliang group of upper Juras slc and lower cretaceous were developod inthe arca of the well. Aocording to the sporopolcn fassils, thelimit betwcen Triassic and Jurassic strata may bo dividd at depth of 4 665m.

Key words: the well Lunnan No,1, striatigraphic divition, fossil evildences