This study was carried out to find physical and mechanical properties of soil in Yongsan project area to support basic data for tidalland reclamation. The main results are as follows. 1. Most of the soils in this area consist of clay and silt, and inorganic materials. 2. Natural moisture contents are ranged from 42.2% to 92.9% initial void ratio, from 1.4 to 2.3 Therefore it takes a longtime in Settlement of considerable depth. 3. Wet unit weights decrease with increasing of the nataral moistare contents as r_t=2. 005-0. 0065w_n. 4. The relationships between compression index. and liquid limit, initial void ratio and natural moisture contents are found as follows respectively. C_c =0. 046+0. 012LL C_c =-0. 068+0.367e_o C_c =0. 056+0. 008w_n 5. Natural moisture content, plastic limit, plastic index, initial void ratio and liquid limit are directly proportional to clay content ratio. The relationships are found as W_n=26. 083+0. 797C_y P_L=14. 223+0. 128C_y P₁=0. 457+0. 492C_y e_o=0. 757+0. 020C_y LL=14. 695+0. 620C_y. 6. Initial void ratio and liquid limit are directly proportional to natural moisture con-tent as follows. e_o=0. 310+0.022w_n LL=6. 275+0.592w_n