We are interested in studying an involutive system defined by a closed non-exact 1-form on a closed and orientable surface. Here we present a necessary condition for the global solvability of this system. We also make some particular constructions of globally solvable systems that motivate the equivalence between the global solvability and the necessary condition, for two cases involving 1-forms of the Morse type, namely, when the surface is the bitorus or when the 1-form is generic. v vi form. In Chapter 5, we complete the cases for Morse forms on the bitorus obtaining an equivalence between our condition and the solvability. The final chapter, in turn, ix yields the equivalence for a special case on which b has rank equal to 1 and supplies more examples. Working with Morse forms is far from being particular: the set of Morse forms is open and dense in the set of the smooth closed 1-forms. All the machinery involved in this part enables us to consider, in the future, the problem when b is a real analytic