Abstract: This paper introduces a new double cell triaxial system (DCTS) for continuous measurement of the volume change of an unsaturated or saturated soil specimen in triaxial test. The DCTS overcomes two critical shortcomings of the conventional triaxial system and the existing modified triaxial cells.It is found that the relative error for the test result of the new DCTS is less than 1.93%. The calibrated results using both the solid copper specimen and the saturated marine clay specimen show that the DCTS is accurate and reliable for continuously measuring the volume changes of unsaturated or saturated soil specimens during consolidation and compression.