Abstract: The Wuchang section is used as a hypostratotype for the Xingshikou Formation in Hebei province within the limits of discontinuous stratigraphic sequence, complicated structure, and dyke intrusion of later stage. To reevaluate the Xingshifou Formation, the Niangniangmiao section which can be divided into two lithologic members in Shanggu town of Chengde County is surveyed. The lower member is coarse clastic sediment with gravel and interbedded sandstone lens, and the upper member is fine clastic sediment with sandstone, siltstone, silty mudstone and occasional one or two layer coal seams. The stratigraphic age of the Xingshikou Formation might be formed in Late Triassic according to paleontology assemblages, pollen assemblages and isotopic data.