Abstract: The sporamorph Kuqaia is an Acritarch fossil similar to animal shell or Gastropoda, which has been commonly used in formation classifications and correlations due to its properties of short geochronology, extensive distribution and easy to recognition. In the past, it was generally considered to be fairly limited in horizon distribution such as Jurassic Yangxia formation, Kangsu for-mation, lower part of Yangye formation in Tarim basin and Jurassic Sangonghe formation and corresponding downhole intervals in Junggar basin, and belong to late or middle-late period of Early Jurassic. The recent research indicates that Kuqaia originated in early period of Early Jurassic, flourished in late or middle-late period of Early Jurassic and may be distributed to Middle Juras-sic.

Key words: Tarim basin, Junggar basin, Jurassic, fossil