Abstract: The principle and the main step of treatment of soft soil in intertidal zone of Lianyungang with cacuum preloading are introduced in detailed through a case and the date of in situ monitoring is analysed deeply, The vacuum pressure of 80kpa is applied for about 100 days to consolidate the soft clay layer with thickness of 10rn. The settlement is about lm. The average degree of consolidation estimated according to the observation data is over 80 G. The undrained shear strength of the soil is elevated remarkably after vacuum preloading. The bearing capacity of the foundation basically reaches the requirement of construction, which show that the vacuum preloading technology is suitable for consolidation of soft soil in intertidal zone of Lianyungang.