This study performed the systematic analyses for a large number of the fossil plants collected from the middle Jurassic Yaojie Formation in Yaojie, Gansu Province. The results show that the flora of the Yaojie Formation is composed of 63 species in 31 genera, including Ginkgopsida of 23 species in 7 genera, Filicopsida of 14 species in 7 genera, Coniferae of 11 species in 7 genera, Cycadopsida of 10 species in 5 genera,Sphenopsida of 4 species in 4 genera, Plantae insertae sedis 1 species in 1 genera. Based on the composition, taphonomy and paleoecology characteristics of the flora, this study reconstructed the ancient flora group and summarized paleoecoloical features of the Yaojie flora through analyzing the burial type and ecology of plant fossils. Four plant communities have been recognized in ascending order as follows: riparian hydrophyte community, llowlandslowslope community, intermontain upland community, and xerophyte community. Based on the overall characteristics of flora, the proportion of taxa in flora, the characteristic molecules and their paleoecological characteristics and sporopollen assemblage, we can infer that the paleoclimate in the Yaojie Basin was warm and humid subtropical climate during the Middle Jurassic. The presence of Brachyphyllum and Czekanowskiales fossils shows that the climate in Yaojie of Gansu had a seasonal variation during the Middle Jurassic.