Abstract: K0-consolidation tests and consolidation tests under constant matric suction were performed on unsaturated undisturbed silty clay along Jiaozhou-Jinan railway line.K0-consolidation tests were carried out to get lateral coefficients of soil pressure in different water contents.Then consolidation tests under constant matric suction were performed through simulating graded confining pressures and overburden loading,and getting soil-water characters curve.We discussed on the soil-water characters and volume transformation rules of unsaturated silty clay.The main conclusions were obtained as follows: lateral coefficients of unsaturated silty clay are fluctuated from 0.51 to 0.61,and varie with water contents;the air entry value of unsaturated undisturbed silty clay is about 25kPa;saturation degree influences consolidation time strongly,and the higher saturation degree the longer consolidation time of unsaturated silty clay.