Method of and apparatus for measuring a space distribution of spacings between point scatterers. An ultrasonic wave is applied to an ultrasonic scattering medium which is an aggregation of point scatterers. Ultrasonic waves, scattered from the medium, are converted into an electric signal. The shape of a power spectrum of the electric signal is determined. A fractal analysis is effected so as to determine a fractal dimension and self-similarity with respect to the power spectrum shape. A spatial distribution of a structural inhomogeneity of the scattering medium is measured in accordance with results of the fractal analysis.