Abstract: The tectonic setting of the northern Bayankala Mountain in Youyun area is located in the eastern segment of the Paleo-Tethys Ocean. Gande Formation of Bayankala Group developed in this area is a flysch formation primarily composed of sandstone and slate, with relatively homogeneous lithological assemblages. Meanwhile, the age of this formation remains highly controversial due to the lack of reliable biostratigraphic evidence. A measured section of Gande Formation was conducted to count the conodonts discovered in the section, which belongs to 11 genera and 14 species. A conodonts assemblage zone Hindeodella suevica-Nicoraella kockeli, with significant stratigraphic age-discriminative value, was identified to fill the biostratigraphic information gap of Gande Formation in this region. The age of Gande Formation in Yunyou area of the northern Bayankala Mountains has been precisely constrained to the Late Olenekian Period of Early Triassic to middle Anisian Period of Middle Triassic. The research could provide references for the delineation of stratigraphic sequence in this region.