In order to explore the plastic cumulative strain effect of red clay under long-term cyclic dynamic load, saturated remolded red clay in Nanchang area was used for cyclic triaxial test under uniaxial loading.The effects of dynamic stress ratio, initial porosity, consolidation confining pressure, loading frequency and drainage conditions on plastic cumulative strain and dynamic pore pressure of red clay were studied.The results of tests indicate that：with the increase of dynamic stress ratio, the deformation curve of red clay transits from gradual stable type to destructive type.When the dynamic stress ratio is less than the critical dynamic stress ratio, with the increase of cyclic vibration times, the plastic cumulative strain and dynamic pore pressure development curves of red clay both show initial rapid growth, and then the inflection points appear and finally tend to be stable.Under the same dynamic stress ratio, the cumulative strain and dynamic pore pressure of the sample increase with the increase of initial porosity and consolidation confining pressure, and decrease with the increase of loading frequency.At the same time, the cumulative strain under undrained condition is larger than that under drained condition.The larger the plastic cumulative strain is, the later the inflection point of strain development curve appears.With the increase of dynamic stress ratio, the softening degree of the soil increases, but at higher cyclic vibration times, the softening degree decreases.