Abstract: The soil residual strain increase model under irregular loads is still an issue to be explored. Existing time-domain integral method is difficult to consider the residual strain effects of soils. A description method of soil residual strain under regular or irregular loads is expounded and combined with the hyperbolic dynamic skeleton curve, a new soil stress-strain relations is deduced, which can consider residual strain well and facilitate programming. Futhermore, this new stress-strain relation is applied in the time-domain integral method of soil layer response analysis to obtain a new time-domain integral method which can consider residual strain effects and a corresponding calculation procedure RS-DYMATLAB program is compiled on the MATLAB platform. Some real experimental data are used to verify this method, and the results show that this method can consider the residual strain effects of soils well, and can be applied as a reasonable and feasible method for nonlinear site response analysis of soil layers.