Abstract: Engineering analysis of recent marine soft soil settlement is based on a traditional one-dimensional drainage consolidation theory of Terzaghi.K. Because of specific engineering-geological properties of the marine soft soil, i. e. high porosity ratio, high water content, high compressibility, and low permeability, the result of calculation is not consistent with actual situation. In this paper, on basis of analysis of SEM data and pressure mercury test, the authors analyze the essential factors of affecting the soft soil consolidation. At last, by means of one-dimensional compression test, the authors compare the theoretical curve of consolidation with the test curve of compression, analyze the causes for deviation of two curves, set forth the mechanism for consolidation of marine soft soil, and put forward a new concept of bound water consolidation.