  We derive an effective Lagrangian for meson fields. This is done in the
light-cone gauge for two-dimensional large-N_c QCD by using the bilocal
auxiliary field method. The auxiliary fields are bilocal on light-cone space
and their Fourier transformation determines the parton momentum distribution.
As the first test of our method, the 't Hooft equation is derived from the
effective Lagrangian.
