As the inside of Jiao—Liao—Ji Paleoproterozoic orogenic/mobile Belt of North China Craton,granitic pegmatites are widely outcropped in Xiuyan area,eastern Liaoning Province.To study these granitic pegmatites is of important tectonic significance.A large number of Paleoproterozoic granitic pegmatites were found in Xiuyan area, which were uniformly classified into granitic melanges and Liaohe Rock Groups.In this paper,through detailed field geological survey and indoor comprehensive study, this set of granitic pegmatitic dykes is disintegrated into a new mapping unit.In this paper,petrology, petrogeochemistry,zircon LA-ICP-MS rare earth trace elements and U-Pb dating of two granitic pegmatite samples in the study area were comprehensively studied to obtain the proto-rock age of granitic pegmatite and to discuss its petrogeochemistry,genesis and tectonic environment.Granitic pegmatites have the main mineral assemblages of K-feldspar+plagioclase+quartz±Muscovite±tourmaline with pegmatitic texture and massive structure.The results of geochemical analysis of rocks show that they have uniform geochemical characteristics. They all showed high contents of SiO2(72.1%~75.3%),Al2O3(13.5%~16.4%),low contents of CaO (1.42%~2.03%),MgO (0.15%~0.76%),P2O5 (0.01%~0.02%%) and TiO2(0.06%~0.17%);the total amount of rare earth elements is low,rare earth enrichment,heavy rare earth loss,the distribution curve of rare earth tilting to the right,obvious δEu anomaly;the trace elements were enriched with large ionic lithophile elements (Cs, Rb, Ba, U) and relatively deficient elements with high field strength (Nb, Ta, Ti).The strength of the zircon CL images of the samples (DST-TW1 and WJG-TW1) was relatively weak,most of the zircons of the former could not reflect the internal structure of the mineral,while most of the latter could show weak oscillating bands,which was consistent with the high U content of the zircons (1253.1×10-6～12861.5×10-6、874.5×10-6～5319.1×10-6).Zircon has since the shape characteristic of the magmatic zircon,but Th/U ratios(0.01~0.26,and 0.01~0.62)is low,show the characteristics of hydrothermal zircon,rare earth distribution patterns in (Sm/La)N—La and Ce/Ce*—(Sm/La)N illustration on partial hydrothermal zircon area,the giant crystal granite dike is likely to be female height of magma crystallization differentiation after the residual magma hydrothermal crystallization,partial hydrothermal properties.The two samples (DST-TW1 and WJG-TW1)studied in this paper were 1864±20Ma(MSWD=0.19)and 1903.6±4.7Ma(MSWD=0.041),the emplacement time ranged from 1.9Ga to 1.86Ga.It is inferred from the rock geochemistry and the formation age that the provenance is related to the S-type granite~1.87Ga around the study area.From tectonic environment,research in paleoproterozoic granite pegmatite formation in the Jiao—Liao—Ji Paleoproterozoic orogenic BelL arc continental collision after stretching the structure of the system,after the main period of granitic magma upwelling,the crust is constantly stretching and relaxation collapse, a large number of residual magma or magmatic hydrothermal upwelling form pegmatite dike,dike or rock mass,the emplacement age from~1.9 Ga to~1.74Ga.Thus,it is speculated that the Jiao—Liao—Ji orogenic belt was in an extensional tectonic mechanism during the tectonic reentry after the collision,and the post-orogenic stage lasted at least 160Ma.