DRG originated from United States and then promoted to Australia, Germany, France and other countries. These countries have been applied the DRG system for many years and accumulate rich experience. The paper deeply compares the history of DRG grouping development, the basic DRG grouping logic, the main variables of grouping, the characteristics of classifying Major Diagnostic Category, partition, basic group and DRG in some typical countries. The paper summarizes the basic principles and main features of DRG grouping in these countries and provides references for the establishment of our DRG grouping which accords with our national conditions.