Abstract: Stress-strain behaviour of saturated,wet,air-dried and oven-dried Fujinomori clay was evaluated by performing a series of one dimensional(1D)compression and triaxial compression(TC)tests including primary loading,global unloading and reloading.In the tests,axial strain rate was changed stepwisely many times during monotonic primary loading with a constant strain rate.Creep fest was also performed during primary loading.Local displacement transducer(LDT)was used in the triaxial compression tests to improve the accuracy of the measurement of vertical strain.In order to evaluate the visco-plastic properties of Fujinomori clay,parameter β was introduced according to the present test results of clay and authors’ previous study.It was shown that viscous property was generally larger in saturated clay than in dried clay;and larger in one dimensional compression tests than in triaxial compression tests.