Abstract: A new nonlinear creep model for clay is developed and used to study the one dimensional creep-consolidation process.The nonlinear creep analysis method is based on the relationship between stress history and secondary consolidation index.It is different from the “equivalent time” concept and can give a better prediction of creep rate for over-consolidated clay.The effects of sample height,stress history,and distance from drainage surface on one dimensional secondary compression behavior during primary consolidation period are investigated by a finite difference method using the proposed model.Analysis results show that nonlinear creep behavior during primary consolidation period is more apparent for over-consolidated soil and the nonlinear analysis method can give a good simulation of the “yield point” obtained by Imai et al(1992)in their special compression tests.