Silt is widely distributed in coast area. Its consolidation is a popular geotechnical engineering issue. Coast silt is always under seasonal wave and tide, which made great influence on the consolidation process. Abundant lab and in-situ tests are used to study on the physical-mechanical properties of Xiamen coast silt. The engineering characteristic of the coast silt taken from Xiamen is evaluated and the relationships between physics and mechanics indexes such as compression coefficient, water content, void ratio, cohesion and internal friction angle are analyzed, and the linear regression equations between silt parameter is established. Then two in-situ tests cone penetration test (CPT) and flat dilatometer test (DMT) are applied to study the properties of coast silt, abundant in-situ test data obtained.