Abstract: Assuming initial pore pressure gradient not less than threshold gradient, an exact analytical solution is presented for one dimensional consolidation of double-layered ground with threshold gradient and the influence of threshold gradient on consolidation behavior is investigated. The results show that the excess pore pressure will not be completely dissipated at the end of consolidation and there is residual excess pore pressure existing in the clay layers which is related to the values of the threshold gradients; the average degree of consolidation considering the threshold gradient in terms of settlement is different from that in terms of stress; the average degree of consolidation defined by settlement with threshold gradient is greater than that without considering threshold gradient and the average degree of consolidation defined by pore pressure considering threshold gradient of which the ultimate value is less than 1 is less than that without considering threshold gradient.