Abstract
By the data from census and housing survey, the distributin type of living spaces well fits in Gibrat distribution (lognormal distribution). This report is about the "τ" (deviation) and the "m" (mean) of Gibrat distribution on the number of tatami (living space) in dwellings and households. Recently, the "б" of distribution is increasing, especially in urban areas such as б largest cities, and this trend is remarkable. In post was Japan the housing construction volume is showing large quantities, and the mean level of dwellings is enlarging year by year, but in spite of 1t, "б" is also apt to increase intensely. These tendencies are the violently increasing phenomena of small units in urban district. Of late, the difference between upper and lower classes on housing is enlarging, for instance in Tokyo, small units under 36m^2 are 50% of all dwellings in 1963.
