In this research 2 new lithostratigraphic units based on studying of 8 stratigraphic sections which outcrops with a considerable thickness in high Zagros (Semirom-Ardal) is introduced. The clastic-carbonate sediments (unit stratigraphic 1) is 314 m in thickness at its type section (station 7). The lower contact of this unit is conformable with the underlying Amiran Formation but its upper contact is unconformable with the red colore clastic sediments (unit stratigraphic 2).The red colore clastic sediments (unit stratigraphic 2) is 220 m in thickness at its type section(station 5). The lithostratigraphic 2 overlies the clastic-carbonate sediments (unit stratigraphic 1) or Gurpi Formation by an unconformity boundary but its upper contact is conformable with the Tarbur Formation. The type sections of both lithostratigraphic units are selected according to the maximum thickness and completed successions in Semirom area (stations 7 and 5, respectively).