A series of tests were conducted for the unsaturated expansive soil using three-dimensional swell-shrinking device. The three-dimensional swell-shrinking characteristics of remolded expansive soils was studied. According to the test results

three-dimensional swelling pressures are unequal. The lateral swelling pressure is smaller than vertical swelling pressure. The swelling pressure of remolded expansive soil is decreasing with wet-dry cycles. And a small strain could bring obvious decreasing of swelling pressure. The logarithmic relation between lateral pressure and strain is proposed. A formula of vertical swelling pressure with initial water content and dry density is given.