Abstract: From Nov. 1978 to Dec. 1979, the writers firstly engaged in a dynamical consolidation project of soft clay foundation for road No. 3, Xingang, Tianjin, and got satisfactory results. From Aug. to Sept. 1979, they used the same method for compactly loose fine sand foundation for a storage yard of the coal wharf at Chinwangtao City.Both cases proved that the dynamical consolidation method is really an effective means for improving soft foundation, especially for loose fine sand. The bearing capacity of the sand foundation at Chinwangtoa City was increased three times after treatment.Therefore, this method is worth while to be used from points of view of efficiency and economics.With field measurements of total stress and pore water pressure, it was discovered that the effective stress increased immediately after compaction,thereby, confirming the instantaneous drainage of the pore water. This is a fundamental requirement for improvement of soft foundation.The main parameters of dynamical consolidation, such as the optimum compaction energy etc. can be determined by the measured data of pore water pressure.The field technology of this method was fully discussed in this paper, including, the process of self-release hook that is suitable for the construction condition in our country.