Fine-grained sedimentary rocks are widely distributed in strata of different geological times and account for approximately two thirds of sedimentary rocks around the globe. Fine-grained sedimentology is a scientific discipline that studies the composition， structure， classification and genesis， sedimentary process and distribution pattern of fine-grained sedimentary rocks. Under the control of tectonic sedimentary background， provenance， climate change， hydrodynamic conditions， volcanic and submarine hydrothermal activities， the rocks vary greatly in terms of age and space， organic matter abundance and lamina structure and combinations， thus making the key issues to the discipline the determination of formation and preservation mechanisms of organic matter， the genesis of lamina structures， the sedimentary hydrodynamic conditions and the sedimentary models in different water environments. Recent major progresses have been made in fine-grained sedimentary petrology and classification， sequence stratigraphic framework setup and temporal/spatial distribution studies， palaeo-water depth and palaeo-environment reconstruction， lamina structure and combination analyses， experimental sedimentology and depositional dynamic condition restoration for shale， as well as establishment of organic matter enrichment mechanisms and depositional models. The future trends of the discipline include the standardization and classification of terminology， the establishment of chronostratigraphic framework for shale， correlation of palaeo-climate and sedimentary models， the determination of organic matter enrichment as well as micro observation and logging evaluation and prediction of macro-distribution of lamina types and combinations. The development of fine-grained sedimentology is of important guiding significance for the distribution prediction of organic-rich shale and the evaluation of shale oil and gas sweet spots/areas， thus further promote the conventional and unconventional oil and gas exploration.
