The stratigraphic definition of the Carboniferous Yanghugou Formation in Ordos Basin is not clear and there are few studies on paleoclimate and paleoenvironment. To determine the age of the Yanghugou Formation, this paper studies the pollen fossils of the Yanghugou Formation in the Wuda section of the western Ordos Basin and restores the paleoclimate through the genetic relationship between pollen and paleovegetation. According to the species and content changes of palynofossils, two assemblages are established: Lycospora noctuina-Stenozonotriletes lycosporoides assemblage and Dictyotriletesbireticulatus-Ahrensisporites guerickei assemblage, which divide the Yanghugou Formation into lower and upper sections. By comparing with Yanghugou Formation in the Baiyantaohai area of Inner Mongolia and the Carboniferous-Early Permian fifth spore belts in the Zhongning-Zhongwei area of Ningxia, the ages of these two spore-pollen assemblages are determined, which are A-B stages and C-D stages of Westphalian, respectively, and equivalent to the Late Bashikian and the Moscovian in the International Age Strata.The spore fossil content of ferns in the lower segment of the Yanghugou Formation is slightly higher than that in the upper segment and the pollen fossil content of gymnosperms is slightly lower, but the overall change not significant, indicating a relatively stable climate of the Yanghugou Formation during the deposition period. The relationship between palynological fossils and ancient plant types is speculated. The ancient plants of the Yanghu Formation were mostly tropical-subtropical. Using the earth's chemical elements, this area should be a warm and humid tropical-subtropical climate.

Yanghugou Formation  /  pollen assemblage  /  the Western Margin of Ordos Basin  /  Wuda area  /  palaeoclimate