The advantage of Pauli-Villars regularization in quantum field theory quantized on the light front is explained. Simple examples of scalar λϕ4 field theory and Yukawa-type model are used. We give also an example of nonperturbative calculation in the theory with Pauli-Villars fields, using for that a model of anharmonic oscillator modified by inclusion of ghost variables playing the role similar to Pauli-Villars fields.