SHRIMP U-Pb isotopic age data of the detrital zircons from muscovite quartz schist of the Beidahe Complex-Group are reported in this paper. It is demonstrated that there are records of tectono-thermal events of the age span 1400 ~ 3035 Ma in the erosion source areas of the Beidahe Complex-Group meta-sedimentary rocks, among which are dominantly magmatic events except for the ca. 2457 Ma metamorphic one. Based on probability of age data, the strongest magmatic event in the source areas is the ca. 1800 Ma one, followed by the 1400 ~ 1700 Ma and Meso- to Neoarchaean ones in weakening order. Metamorphic age of ca. 863 Ma suffered by the Beidahe Complex-Group was obtained as well. Therefore the sedimentation age of the Beidahe Complex-Group is between 1400 Ma (the youngest detrital zircon age) and 863 Ma (metamorphic age), rather than the Palaeoproterozoic that was previously adopted. At least the Beidahe Complex-Group is younger than 1800 Ma, because 46% of the detrital zircons are ca. 1800 Ma in age. The data also imply that there are Meso- to Neoarchaean continental crusts in the source areas. In addition, the data of this study combined with other available data provides constraints on the age of the ophiolite of the Zhulongguan Group in the studied area, that is, the ophiolite most probably formed in the early Palaezoic instead of the early Mesoproterozoic.