On the basis of the distribution and sedimentation of disaccate pollen from recent coniferophyte, it is inferred that there were subalpine and middle mountains on the Jianhu Uplift during the Early Miocene, where Abies, Picea, Tsuga, etc. grew. The geological records of a continuous section of inland basins show that as the crust rose, the area of mountains expanded and the land was uplifted, disaccate pollen increased progressively with variant genera and species appearing in regions of fixed height adapted to their growth. During the crustal subsidence and erosion, the case with disaccate pollen is contrary. On the basis of the variational model of disaccate pollen in the continuous section coupled with the correlation of the disaccate pdllen curves before and after the Sanduo Movement that occurred between the Neogene and Paleogene in the northern Jiangsu South Yellow Sea Basin, the author finds that the lower part of the "model" is commonly absent in the area; therefore it is inferred that the Oligocene is not complete. The global sea level fluctuation is closely related to the climatic changes and microflora succession. According to this relation, the author considers that the Upper Member of the Sanduo Formation is Middle Oligocene in age. The Upper Oligocene is lacking universaly in the northern Jiangsu-South Yellow Sea Basin.