Dunhuang block was mainly composed of Precambrian TTG gneisses and metamorphosed supracrustal rocks, and numerous Paleozoic granitoids emplaced in Dunhuang block. Aiming to better understand the tectonic evulotion of Dunhuang block and the geodynamic significance, in this paper, Danghe reservoir granite and Shazaoyuan granite, two granitic plutons in Sanweishan area were chosen to study by means of petrography, geochemistry, zircon U-Pb chronology and Hf isotopic analyses. The results show that: (1) the two granites have different rock assemblage types, granodiorite and muscovitebearing granite for Danghe reservoir granite while mediumcoarse monogranite and finegrained monogranite for Shazaoyuan granite. Zircon U-Pb dating shows that the two granites were emplaced in 461.7~438.1Ma and 457~433.9Ma, respectively. (2)Danghe reservoir granite shows Itype granite features,with εHf（t）ranging from -5.5 to +2 while twostage model age（tDM2）was varied in 1.3~1.7Ga. Under the consideration of geochemical characteristics, we propose that the source rocks were metabasic rocks of Mesoproterozoic ancient crust with part of the juvenile crust. Shazaoyuan granite shows Stype granite features,withεHf（t）ranging from -8.6 to -0.9 while twostage model age （tDM2）was varied in 1.5~1.9Ga, and the source rocks were metagreywackes of late Paleoproterozoic to early Mesoproterozoic ancient crust. (3) Both of the residual rocks of two granites were the granulites which mainly consisted of garnet,hornblende and plagioclase, and part of the source rocks may have a relationship with the assemblage and breakup of Columbia supercontinent. (4)These two granites were formed in an orogenic movement, and the Early Paleozoic orogenic event could be brought forward to 4617Ma while ended later than the Central orogenic belt. Meanwhile, both the timing limitation and the temporalspatial distribution of granites of Dunhuang block are in correspondence with TianshanBeishan orogenic belt. Above all, we propose that Dunhuang block was involved in the orogenic event of the Central Asian orogenic belt, but was unaffected or just affected in early stage by the Central orogenic belt.