We studied the scalar electrodynamics ($SQED_{4}$) and the spinor electrodynamics ($QED_{4}$) in the null-plane formalism. We followed the Diracs technique for constrained systems to perform a detailed analysis of the constraint structure in both the
ories. We imposed the appropriated boundary conditions on the fields to fix the hidden subset first class constraints which generate improper gauge transformations and obtain an unique inverse of the second class constraint matrix. Finally, choosing the null-plane gauge condition, we determined the generalized Dirac brackets of the independent dynamical variables which via the correspondence principle give the (anti)-commutators for posterior quantization.
We have studied the null-plane hamiltonian structure of the free Yang-Mills fields and the scalar chromodynamics ($SQCD_{4}$). Following the Diracs procedure for constrained systems we have performed a detailed analysis of the constraint structure of
both models and we give the generalized Dirac brackets for the physical variables. In the free Yang-Mills case, using the correspondence principle in the Diracs brackets we obtain the same commutators present in the literature.
