Abstract: The effect of the change of transport parameters on contaminant transport through GCL has been analyzed.The analysis includes the concentration ratio at the base of a GCL,advective and diffusive mass flux,and total accumulated contaminant mass through the liner per unit area.Decreasing hydraulic conductivity and diffusion coefficient may delay the increasing rate of the concentration ratio at the base of a GCL.Hydraulic conductivity has great effect on advective mass flux,and change rate of diffusive mass flux.Diffusion coefficient has great effect on the maximum diffusive mass flux.When hydraulic conductivity is high,diffusive accumulated mass can be neglected.Using advective accumulated contaminant mass instead of total accumulated contaminant mass will cause more less error.But when hydraulic conductivity is low,which is common for GCL,the neglect will lead to big error,especially on the condition of diffusion coefficient is high.