Resumo. The intense process of territorial occupation, the unsustainable use of natural resources and the destruction of green areas throughout the nineteenth century are the main reasons for the intense devastation of Mixed Ombrophylous Forest. In an effort to forestry protection and its development, Brazil has adopted as one of its environmental policy, the creation of the Conservation Units System. However, an alternative still rarely used for the regulation of stockpiles timber in the state is by means of the Conservation Unit of Sustainable Use. At this point, it is intended to propose a regulated use for natural resources in protected natural areas. Therefore, two forms of existing Conservation Units were selected to this end it has been proposed the creation of a new modality, called “Private Reserves for Sustainable Development (RPDS).” The Integral Protection Units have played significant role in preserving the biome of Mixed Ombrophylous Forest. In contrast, the Sustainable Use Conservation Units are inexpressive in the biome and need an effective regulation to perform their ecological and social function. Measures to encourage private forests conservation and the sustainable use of timber and non-timber resources, in addition to the instrumental currently used, may contribute being greatly effective in the conservation and recovery of the biome.