Abstract: In this study,a new type of landfill leakage method based on a transmission line model was proposed,and a non-uniform transmission line model was constructed.The ranging equation was deduced by using the electrical parameters of the boundary and the basic principle of voltage continuity in the two boundaries of the leakage area.The characteristic impedance and transmission coefficient of the transmission line were calculated from the electric parameters of both ends.The experimental results showed that:1) at the frequency of 30 MHz,the difference of the attenuation and phase constants between the leakage and non-leakage area reached a maximum value;2) at the same frequency,the values in the leakage area were bigger than those in the non-leakage area;3) with increase of frequency,the characteristic impedance modulus decreased and the radiation angle increased;4) asynchronous sampling had some effects on measurement accuracy.Therefore,to improve the ranging precision,high detection frequency should be used,and synchronous sampling of both electrical ends should be ensured.