The latest progress of the studies on reservoir's fine description of petroleum in China is shown as the following 12 aspects, fine earthquake technology-based complex structure study, complex buried hill lithology recognition technology, fine prediction technology of reservoir through combination of well data and seismic data, characterizing techniques for fissures of low permeable reservoir, classification of microscopic pore structure of conglomerate reservoir, interlayer insulation features based on the data of dense well pattern, water flooded layer interpretation of conglomerate reservoir, reservoir variation law during the development of oilfields, flow channel identification technology of conglomerate reservoir, quantitative classification evaluation of low permeable reservoir, configuration modeling of fault block oil reservoir and multidisciplinary comprehensive characterization technique of residual oil, etc. At present, in the fine description research of reservoir there exist the following eight aspects of problems, mainly including interpretation of microstructures (especially low sequence faults) failing to meet oilfield development needs, many difficulties in single sand body boundary features and interwell prediction, fracture characterization and geological modeling, many difficulties in the quantitative prediction of carbonate fractured-vuggy reservoir, logging interpretation of complex reservoirs still needing to be studied continuously, difficulties in inflow channel identification, a single remaining oil characterization method difficult to meet the production needs, and management status of fine reservoir description result that cannot meet the work requirements. Finally, the development trend in the fine description of reservoir is pointed out.