Abstract: The siliceous rocks of Middle Devonian Hanjiga Group are well developed in Jinghe County, Xinjiang. The research about the genesis of these siliceous rocks has important significant to analyze the sedimentary environment, basin structure, regional geological structure and regional dynamics evolution. Through carrying out 1:50000 geological mapping, profile measurement, petrological and geochemical analysis, the distribution, origin and formation environment of Hanjiga siliceous rocks have been studied. The results show that these siliceous rocks were formed in the bathyal depositional environment with relatively weak hydrodynamic conditions, belonging to the siliceous rocks of volcanic causes mixed with turbidite formation.