This paper illustrates the Cretaceous and Palaeogene palynofloras and climatic belts and deals with distribution of dinoflagellates and acritarchs. In view of the relationship between organic rocks and climatic environments and that between petroleum and phytoplanktons, the probably advantageous areas to the formation of organic rocks are drawn. This paper shows the Cretaceous and Palaeogene palynofloras and climatic belts and deals with distribution of dinoflagellates and acritarchs. In view of the relationship between organic rocks and climatic environments and that between petroleum and phytoplanktons, the probably advantageous areas to the formation of organic rocks are drawn .