Abstract: The circuit equations of variable-impedance transmission lines are usually solved by numerical circuit simulation with simulation code such as PSpice. The commonly-used method is the equal-length segmentation method which divides the transmission line into many small sections with equal length. The paper proposes a different segmentation method, in which the small sections are with equal impedance difference. A transmission line with exponential impedance change is simulated with the two methods. The results show that, with the proposed method, the simulation converges to the true solution more quickly.