Subfossil trunks of oak (Quercus robur L. and Q. petraea Lieb.) are fundamental for construction of long dendrochronological standards for southern Poland. In the last three years over 400 new oak trunks from alluvial deposits from the basins of the rivers Vistula and Odra were analysed. Most trunks came from the last 2500 years and the produced local chronologies permitted for improvement of the standard chronology POLAND2, covering the period 474 BC-I 555 AD. Subfossil oak trunks from several sites in the river Vistula basin (Grabie, Wolica, Podolsze and others) and from alluvia of the river Odra in Wrocław enabled construction of a new long chronology C_3000E, spanning the years 1795- 612 BC. This chronology was absolutely dated through teleconnection with standards for southern Germany. A row of floating chronologies, dated with the radiocarbon method, was established for the older periods of Holocene. They cover the following intervals: ca. 670-400 BC, ca. 2200-1900 BC, ca. 3400-3100 BC, ca. 3800-3600 BC and ca. 6650-6150 BC. Subfossil oak chronologies constructed by the author, together with standards based on living trees, monuments of wooden architecture, and archaeological timbers from Wielkopolska (449- I 994 AD), Lower Silesia (780-1994 AD) and Małopolska (910-1997 AD) practically allow for absolute dating of oak timbers from the area of southern Poland coming from the last 4000 years.