The timing of closure of the Paleoasian Ocean is hotly debated in Beishan area, which is located in the middle part of the Central Asian orogenic belt. The Early Carboniferous is one of the key periods when tectonic plates changed drastically. The unconformity between the Lower Carboniferous Lütiaoshan Formation and the Lower or Middle Devonian has been considered as an important evidence of the Late Paleozoic tectonic uplift. However, the age of the Lutiaoshan Formation is controversial and therefore limits the further discussion of the tectonic evolution. This paper proposes an Early Carboniferous to earlier Early Permian age of the Lutiaoshan Formation based on ammonites Gastrioceras and Branneroceras from the Suishishan section, as well as two LA-ICP-MS zircon U-Pb ages of volcanic rocks from the Tianshuijingbei and Suishishan sections, which are respectively 296.8±3.5Ma and 311.1±3.2Ma. The Beishan area translated from ocean to rift basin from the Early Devonian to Late Carboniferous. The unconformity between the Upper Carboniferous and the Lower or Middle Devonian implies the tectonic uplift caused by ocean-land transition.