Abstract: The fossil plants Cupressinocladus elegana and Frenelopsis are common in Lower Cretaceous strata in China. In the Qilixia section of Xuanhan, Sichuan, the strata originally assigned to the 2 nd lithological member of the Upper Jurastic Penglaizhen Formation also contain the above-mentioned fossils. Therefore the authors consider that the strata should be of Early Cretaceous age and can correlate with the related strata in neighbouring areas, East China and South China. The fossil plants Cupressinocladus elegans and Frcnclopsis sp. arc the important biomarker of the Jurassic and Crctaceous boundary in the central and eastern parts of the Sichuan basin. The distribution and paleogeographical environment of the Frenelopsis-Cnpressinocladus assemblage in South China are discussed in this paper.