  In this paper we investigate quantitatively statistical properties of
ensemble of {\it land prices} in Japan in the period from 1981 to 2002,
corresponding to the period of bubbles and crashes. We find that the tail of
the distributions of ensembles of the land prices in the high price range is
well described by a power law distribution, $ P(S>x) \sim x^{-\alpha} $, and
furthermore that as the power-law exponents $ \alpha $ approached to unity, the
crashes of bubbles occurred.
