For rebuilding the paleoclimate and paleoenvironment during the early- middle Jurassic in the Yanchi area of the Ordos basin, we analysis the palynological characteristics and clay minerals of the core Ningdong- 2, sporopollen assemblages and sporopollen spectra were established. The lower part of the Yanan Formation is the Inaperturopollenites- Psophosphaera- Protopinus assemblage, whose age is the late Toarcian of Early Jurassic. The upper part of this formation is the Cyathidites- Deltoidospora- Cycadopitees assemblage, whose age is early Middle Jurassic. The boundary of lower and middle Jurassic is located between 2144. 5~2153. 0 m of the core. The paleoclimate and paleovegetation established by pollen spectrum shows that the late Toarcian of early Jurassic period was a warm temperate semi- humid climate whose vegetation type was coniferous forest. The early Middle Jurassic was generally subtropical humid climate, whose vegetation appearance transformed from coniferous broadleaf mixed forest- grass type to the coniferous forest- dilute grass type. From the late Toarcian of Early Jurassic period to the early Middle Jurassic period, the humidity changed from semi- humid to wet while the temperature changed from low to high. This climate change trend was also found in clay minerals analysis. The climate shift has had a clear role in promoting coal gathering in the region.