La Constitucion nacional ha traido sustanciales reformas a la figura juridica de la convencion colectiva. La nueva vision de la Constitucion renueva principios esenciales que regian dicha figura y que tratan de solucionar desde el punto de vista juridico los problemas sociales, a traves del reconocimiento de derechos fundamentales, tales como la libertad sindical, que guien la aplicacion juridica a una verdadera justicia social. Abstract National Constitution has brought substantial reforms to the figure of collective convention. The new vision of the Constitution renews essential principies, which ruled that figure and try to solve social problems from a juridical point of view, through the recognition of fundamental rights such as trade-union freedom which could guide the juridical application to a real social justice.