Abstract: Geochemical studies on the Jianggaleisayi granitic gneiss suggest that the rocks are characterized by SiO2>70％ ，Al20 3>13％ ，Na2O +K2O =7．52％ ～8．91％ ，and with ASI=1．10～ 1．27，belonging to syn-eollisional S-type granite．The chondrite-normalized REE patterns are right-inclined，with a clear"V"trough，belonging to the granite of crustal source．The midocean ridge granite-normalized trace element spidergrams are characterized bv enriched LILE(such as Rb and Th)and depleted HFSE(such as Nb，Zr，Hf，Y，and Yb)．0n the R1～ R2 tectonic discrimination diagram they are plotted in the typical continent-continent syn-collisional granite field．The CL investigations reveal that zircons from the granitic gneiss are generally colourless，transparent and eu'hedral。and have distinct zoning of oscillatory bands，typical of magmatic origin．By means of LA-ICP-MS U-Pb isotopic dating．the zircons yielded a weighted average 206Pb／238U age of 923±13(2σ)Ma and indicative of Neoproterozoie time．Combined with the Neoproterozoic syn-collisional granite obtained from adjacent area，it is suggested that a collision and convergence between microcontinents in NW China took place during the Neoproterozoic time．This is very important not only for determining the existence of Neoproterozoic orogeny and for reconstructingthe tectonic evolution of the ancient continents in northwestern China，but also for providing constraints for discussing the relationship between the HI 一UHPM rocks and their country gneisses in the study area.