It has long been regarded that the only Early Paleozoic occurs in North Daba Mountain, but this idea may be challenged. The Taohekou Formation in North Daba Mountains is a volcanic sedimentary succession which preserves relatively complete sedimentary records. Detrital zircon U Pb ages from sandstone collected at the same position were measured by the LA ICP MS method in this study. 62 sets of age data were obtained for the samples 12YMN1 and 12YMN11, which have redefined the formation age of the Taohekou Formation and provided constraint on the evolution of early Paleozoic tectonic in North Daba Mountains. The ages of 11 young zircons indicate that the Taohekou Formation deposited no earlier than Early Devonian. The concordant ages of detrital zircons show that the Taohekou Formation was sourced mainly from trachyte, intrusive rocks and basalts with time range from 407Ma to 434Ma. The age and CL images for magmatic detrital zircons indicate that there occurred three stage magmatism, that is, Early Silunian, Middle Silunian and Early Devonian, corresponding to the intrusive rocks at 431~439Ma, trachyte of the Banjiuguan Formation at 4269Ma, and basalts of the Taohekou Formation at 4143Ma, respectively.