  We discuss the Hamilton-Jacobi approach for a constrained system. We obtain
the equation of motion for a singular system as total differential equations in
many variables. We investigate the integrability conditions without using any
gauge fixing condition. The path integral quantization for systems with finite
degrees of freedom is applied to the field theories with constraints. So, we
apply the Hamilton-Jacobi quantization to obtain the path integral of the
Landau-Ginzburg theory.
