Abstract: In order to study the terminal response characteristics of abruptly non-uniform line on a lossy ground exposed in radiation field, the terminal response formula of abruptly non-uniform transmission line above a lossy ground is derived based on transmission line model and microwave network parameters transition matrix. The terminal response of the abruptly non-uniform line can be calculated accurately based on the derived formula. To confirm the validity of the theory, the abruptly non-uniform transmission line with a converter is analyzed and calculated theoretically. The terminal response of transmission line structure with different conductivity is analyzed and calculated theoretically:the influence of different conductivities on the terminal conducted current is less than 3dB. Based on practice, the terminal response of non-uniform transmission line with a converter above a lossy ground, whose conductivity is 0.01S/m, is measured. It is shown that the theoretical results are in agreement with the measured results. This proves that the method of microwave network transition matrix in this paper is especially suitable for the calculation of the response of the response of the abruptly non-uniform lines.