Abstract: Because of its natural geographical conditions, the Tarim Basin witnesses unique geotechnic properties such as low bearing capacity, poor geological conditions, poor water quality, high salt content, etc. Based on the geotechnic survey for the four 50 000m³ oil tanks in Tarim, analysis and study are performed on the engineering properties of local geotechnics, the measurement of geomechanical index, and calculation of settlement. It is pointed out that, during geotechnical survey, consideration shall be given as well to the special natural and geographical conditions especially to soil corrosiveness, salt expension and sink properties. The physico-mechanical index of the saliferous clay shall be measured and evaluated with the consideration pf the treatment method and the possible state of the structures during their operation, so as to present the real geotechnical conditions. In order to gain a practical result, the settling saliferous area under the comprehensive effect of base, foundation and tanks shall be accordingly calculated by means of FEM (finite element method), while taking into account the sinking effect.