Located within the Ruyang Basin in Western Henan, the dinosaurbearing stratum, named the Mangchuan Formation, and its geochronology were poorly studied up to now. On the basis of geological survey, stratigraphic sequences and geochronology, the dinosaurbearing deposits was discussed in this paper. Based on the SHRIMP UPb dating (130~133 Ma) of the zircons from tuffs in the Early Cretaceous Jiudian Formation underlying the dinosaurbearing stratum, and in combination with stratigraphic succession, deposits and contacts between lithological units, it is concluded that the dinosaur  bearing stratum and the biota should belong to the late period of Early Cretaceous.