To provided a method and apparatus for measuring the degree of compaction applicable at low cost even to vibrations having high acceleration values.

A technique is provided for measuring the degree of compaction during a ground surface compacting operation using a rolling machine, such as a vibrating roller or a vibrating plate, having an upper structure and a vibrating bottom structure and driven at a predetermined exciting frequency. The amplitude value of vibration of the bottom structure relative to the upper structure in the exciting frequency range is determined and the amplitude value of vibration of the bottom structure relative to the upper structure at a frequency equal to or less than 60% of the exciting frequency is also determined; the ratio of the two kinds of amplitude values is employed as the measurement of the current degree of ground surface compacting.