In this paper the finite-difference time-domain (FDTD) method and the transmission lines (TL) method are used respectively in the calculation of voltage standing wave ratio (VSWR) in an axisymmetric coaxial connector with nonuniform medium. Numerical results between the two methods are compared; more details of signal propagation in the connector can be given from the FDTD method, but the TL theory used is more simple and satisfactory results can also be obtained; the experimental result is in agreement with the calculations.