After a general presentation of the Gabon. This italian environmental surveys visit the primeval forest of Mingouli, 100000 ha of tropical forests which is necessary to protect from an excessive deforestation. The Gabonese's flora is probably one of the richest of Tropical Africa. Among the 8000 species some medicinal plants are very interesting and several research centers are working on this species and also with the traditional medecine knowledges. They make proposals for a sustainable development of the forest resources.