Ocna Dej is an iconic locality for salt mining in Transylvania, being located in the north - north-western area of the Middle Miocene sedimentary basin of Transylvania. In this salt the fossils are rare and refer strictly to plant remains (fragments of wood, pine cones, etc.). A sample of charred wood collected from the area of Ocna Dej salt deposit of Middle Badenian age (Wielician) was submitted to a microscopic study for a taxonomic assignation. It was identified as Cupressinoxylon sp. aff. Thujoxylon sp. as a remain of the synchronous vegetation. This wood type is found for the first time in Ocna Dej salt and could contributes to the paleo-environmental reconstruction of this area. Obviously, wildfires occurred at that time around the marine sedimentary basin of Transylvania.