This book addresses the principles and methods for determining petroleum source rocks based on fossil spores and pollen. It is known that pollen and spores in a petroleum reservoir are from a specific source rock. Studying petroliferous basins in China, we discovered that there are often as many as three different sources of the microfossils: the source rocks, the rocks along the pathway, and the reservoir rocks. Therefore, fossil spores, pollen and algae from inland and coastal shelf petroliferous basins are analyzed and illustrated to show this complex process. Furthermore, the organic origin theory of oil is proven and environmental characteristics for hydrocarbon source-rock formation are discussed. Along with the geochronical and geographic distribution of non-marine petroleum source rocks in China, the mechanisms of petroleum migration following the pathways to the reservoirs are investigated. It will be a valuable reference work as well as a textbook for a wider research areas ranging from stratigraphy, palynology, palaeontology and petroleum geology.