Taking the soil of Central Fishing Harbor of Tianjin undrained and drained by vaculty as an example�� we made detail analysis on draining condition of soil��element and distribution of soluble salt in this Harbor area and scratched its influence on IP ��pH and engineering property of soil�� The authors found out that the soluble salt content of the undrained was higher than of the drained��and the contents of Na + and Cl �� in both nearly take up 50% respectly�� The content of other soluble salt was very low��and along with the deepening of sampling��the content variety regulation was nearly the same among Na + ��Cl �� and the total contents of soluble salt�� To the same kind of cohesive soil��IP is different for various contents of soluble salt in the soil�� The relationship between IP and soluble salt contents were nearly the same for the drained and the undrained��but the variety range of IP in the undrained was much larger��