The purpose of this study is to analyze the area table of twenty editions of the DDC in order to identify what major changes have been made chronologically. The summaries about which were discussed according to the edition order about the change processes of the most extensive area table of the DDC auxiliary table are as follows. 1. It is from the 17th edition that area table appeared as a special auxiliary table in DDC for the first time and the method of classifying areas like from 930 to 999 which is regional history in history class was taken before the introduction of independent area table. 2. The entry numbers in which the area table was applied increased continuously until the 18th edition but the applied entry number was rather decreased in the 20th edition especially the number was mainly decreased in history class, this is the result of the fact that the entry was classified by area table without enumerating each regional history in history class except for the basic area since the 17th edition but recently at least the area of over national unit according to the necessity of enumerating the entry in regional history within history class. 3. The relocation or revision of area table was made according to the literary warrant of the relevant area by period political and administrative conditions and the request of related organization or classifiers of the area rather than by the topographical features therefore the revision was made chiefly about the highly interested Europe Northern America especially the United States. 4. The entry numbers which were expanded according to area indicate that gradual improvement for the international feature as the revision of edition is repeated is made but because of the expansion of Northern America, especially the United States, regional disproportion is represented by the occupation of 56% in the entire entry numbers of the United States in case of the 20th edition. Lastly, the reasonable reform plans of area table will have to be groped on the basis of the results of analysis above and the consideration about the problems in the development of area table of DDC and the other main classification systems.