Lithological geochemical and geochrological study was carried out for the Dahongshan granite in the southeastern margin of the Tarim Craton. LAICPMS dating for the zircons from the Dahongshan granite yields a weighted 207Pb/206Pb age of 17323±74Ma, revealing late Paleoproterozoic granites in the Tarim craton. δ18OVSMOW values of whole rocks range from 76‰~86‰. The granite is rich in Si (SiO2=7114%~7585%) and alkali (Na2O+K2O=832%~994%). REE distribution diagram shows an obvious rightdipping seagullshaped distribution, and strong Eu negative anomaly. Trace element analysis shows that the granite has high contents in Rb (809×10-6~129×10-6), Th (173×10-6~286×10-6), Y (62×10-6~220×10-6), Ga (281×10-6~446×10-6) and Nb (526×10-6~145×10-6), and low in Sr (122×10-6~793×10-6), with high Zr+Nb+Ce+Y and 104×Ga/Al, suggesting that the granite has the geochemical feature of Atype granite. In combination with Sc/NbY/Nb diagram, the Dahongshan granite (which belongs to A1type granite) formed in the low pressure setting. Zircon saturated temperature TZr, calculated from 18 granite samples, ranges from 73245℃ to 112833℃ (averaging 9163℃), suggesting a high temperature. The Dahongshan granite was the product of partial melting of the lower crustal material due to asthenosphere upwelling or the mantlederived magma underplating at high temperature and low pressure. The Dahongshan granite, which records not only the whole transformation process from compression to extension but also high thermal event in the Tarim craton after aggregation of Columbia supercontinents, the tracer of the initial stage of largescale breakup of the Tarim craton.