Abstract: This paper presents and analzes the monitored results of the surface settlement, subsection-settlements at a soft soil ground treated with vacuum drainage preloading in the coastal region of Tianjin. The total surface settlements reached about 80 to 160 mm. They were composed of the construction settlement and the pre-construction settlement. By subsection-settlement monitoring, the main settlement happened in the dredged fill and marine soft soil. The disturbed soil which produced by construction induced the avoidable errors of the subsection-settlement. With drainage strips, the characters of soils were changed. Through theoretic deduction and practical calculation on the soil consolidation degree, the results suggest that the correlative way in the foundation treatment manu should be adopted and the immediate settlement should not be ignored. At the site of the vacuum drainage preloading, the special character of the soft soil and its influence on the construction of excavation, pile foundtion etc should be investigated further more.