This study is to find some clues about background or causes of the mass supply of apartments in Korea in terms of correlation analysis using 30 indices extracted from the representative housing statistics data. Some findings include that the supply ratio of apartments is deeply related to 'average floor area ratio' and 'the construction amount of Dagagu housing and Dasedae housing' from the perspective of housing flow. Instead, from the perspective of housing stock, the supply amount of apartments is strongly related to 'housing redevelopment construction' and 'housing construction by public sector'. These indices are involved deeply in the spread of apartments, however, because the indices that used in the analysis are mutually highly related and the indices related to housing policy or system are absent, a critical index for the spread of apartments was not found.
