Abstract:The neocarchean granite is widely developed in the Liujiang area of eastern Hebei, which is the key to solve the study of the formation and evolution of the early continental crust in the east of North China Craton, so it has been widely concerned by many scholars. This paper studies the geological, geochemical characteristics, zircon U- Pb dating and Sr—Nd isotope geochemistry of biotite monzogranite in Liujiang area, aiming to determine its origin and geotonic significance. The rock formation age of (2559±25) Ma was obtained by LA- ICP- MS Zircon U- Pb dating, formed in the late Neocarchean; The geochemical analysis of the whole rock shows that it is quasi- aluminum—weak overaluminum, high potassium calcium- alkaline series potassium rock, Enrichment of large ion lithoophilin (LILE, for instance: Rb, Ba), Loss of high field strength element (HFSE, for instance: Nb, Ta, Ti), The right- leaning distribution pattern with light rare earth enrichment and heavy rare earth loss, The Eu abnormalities are not obvious; \[n(87Sr)/ n(86Sr)\]i value ranged from 0.701172 to 0.701412, The \[n(143Nd)/n(144Nd)\]i value ranged from 0.509341 to 0.509375, Characteristics of a εNd(t) value of 0.4~1.1. Combined with the existing research results, it is believed that the biotite granite in this study has the typical geochemical characteristics of type I granite. There is the addition of mantle source material in the diagenetic process, which is formed in the island arc environment after the arc formation of the active continental edge—land collision.