Presented are the state of art and potentials of dendrochronology in Slovenia. The results of the investigations in the Ljubljansko barje are several tree-ring chronologies that cover parts of the 4th and the 3rd millennium B.C. The wood of ash and oak trees was mainly used in the Ljubljansko barje for the construction of the pile dwellings. The characteristics of waterlogged archaeological wood preserved underwater or buried in the soil in the Ljubljansko barje, are described. If the goal is to preserve it, then it must be prevented from desiccation. We present a strategy of its conservation treatment.