Abstract: With extensive conducting of glotal petroleum exploration and development as well as developing study of geologic theories, people begin to pay more and more attention to studies of oil-gas reservoirs. It has become a new study direction to studies physical properties and space features of oil-gas reservoirs from different angles and to set up a reservoir-geology model by studies of outcrop reservoir and downhole geology. Now, reservoir sedimentology has been developing from pure theory to application and the interpretation and prediction of oil-gas reservoirs go from qualitative to quanhtative ways. The paper tells about the study trend, types and geochemistry of China's reservoirs.