Capacity prediction is a key step in oilfield production.It is difficult to predict reservoir capacity quantitatively.Therefore,the classification of reservoir capacity is usually carried out first to provide a basis for quantitative prediction of reservoir capacity.By analyzing the factors affecting the reservoir capacity in the Huizhou depression of Pearl River mouth basin,191 core capillary pressure curves which can reflect the petrophysical characteristics of reservoirs were used to classify reservoirs into three categories.Then,through combining reservoir classification with capacity classification,the classification limits of reservoir oil production index per meter were determined as 12 and 2 m ³/(d·MPa·m).The comprehensive evaluation index Z,which combines the macroscopic and microscopic physical parameters of the reservoir,was used to divide the reservoir capacity,and finally the reservoir quality index was used to identify the reservoir capacity category of the whole well.Using the capacity classification and identification method,the authors divided the capacity categories of all test sites in the study area,with the accuracy rate over 90%.The method has a good application effect and deserves promotion.