A novel finite difference time domain （FDTD） method has been introduced to analyze multi-conductor transmission lines terminated with frequency-dependent loads. The admittance of frequency-dependent loads can be modeled by rational functions by using vector-fitting, then converting these functions into time-domain by inverse Fourier transform （IFT）. Based on the piecewise linear recursive convolution （PLRC） method, the relation between voltage and current of admittance parameters are deduced. Incorporating the formula into multiconductor transmission lines （MTL） FDTD equations, we get the general formula of MTL FDTD dealing with frequency-dependent loads. In simulating a typical circuit, the results agreed well with the results obtained by using the state-variable transmission model. It shows the method is valid in dealing with frequency-dependent loads.