In this article, we study the vertices DDV and D* DV with the light-cone QCD sum rules. The strong coupling constants g(DDV) and f(D*DV) play an important role in understanding the final-state re-scattering effects in the hadronic B decays. They are related to the basic parameters beta and lambda respectively in the heavy quark effective Lagrangian; our numerical values are smaller than the existing estimations.