The parking problem is caused by the parking demand. The ratio of parking demand at multi-family housing sites has been increased significantly, therefore several parking problems have occurred. The goal of this study is to investigate the parking demand per housing size of public-sized apartments, and to prepare that with the architectural regulations about parking supply. According to the results of this study, the parking demand of the small size housing unit(exclusive size：60 $m^2$ below) shows 1.09 car per the unit. and that of the medium size housing unit(exclusive size：60 $m^2$ over 85 $m^2$ below) shows 1.34 car per the unit. The parking demand of the small size housing unit was exceeded 56% more than the legal supply limit, and the parking demand of the medium size housing unit was exceeded 34% more. It is means that the level of architectural regulation about parking supply was not enough than the parking demand. So, it needs recon-sideration about the architectural regulations of parking supply.