Abstract: Abstract：Regional mapping and isotope dating indicate that the upper and lower subgroups of the Huade Group are located in stratigraphically equivalent horizons rather than have an overlying and underlying contact relationships, and that the Bayan Obo Group in the Shangdu area is also a part of the Huade Group. According to a detailed structural analysis and stratigraphic sections，the stratal sequences of the Huade Group have been reconstructed；the group may be subdivided in ascending order into the Maohuqing Formation，Gejiaying Formation and Sanxiatian Formation. Zircons from the complex intruded into the Huade Group yielded U-Pb ages of 1 808 Ｍａ, 1 853 Ｍａ， 2 091 Ｍａ and 2154Ma suggesting that Huade Group formed in the Paleoproterozoic rather than Meso- and Neoproterozoic as thought previously. The Huade Group underwent at least two phases of deformation：the early phase of deformation gave rise to ENE-trending synclinorium and the late phase was marked by tectonic superimposition，forming NNW-trending folds. The main phase of deformation likely occurred in ~2.0 Ga B．P.The deformation of the Huade Group is related to a Paleoproterozoic orogenic event along the northern margin of the North China Craton, which has great significance for the study of accretion and breakup of the North China Craton.