Abstract: The methods of small-strain triaxial tests on soft clay are collated and summarized, including those using Hall-effect sensors, LVDT, bender elements and resonant columns. To discuss the effectiveness of the Hall-effect sensors on getting clay property in small strain, the triaxial tests with the Hall-effect sensors are performed on Shanghai soft clay. A conclusion is drawn that the elastic modulus of clay in small strain (0.01%~0.1%) can be measured by using the Hall-effect sensors. Finally, it is advised that the LVDT and bender elements should be applied in measuring clay property in smaller strain (0.001%~ 0.01%).