According to drilling data, the use of strontium barium method, boron element, boron and gallium ratio method, rubidium potassium and sodium potassium ratio to calculate the sedimentary aqueous environment of the Late Carboniferous (C2b, C2h, C2k) of Santanghu Basin, combination of all methods show that the deposition is terrestrial environment, mainly, the general media for the ancient water fresh is brackish environment[m (Sr)/m(Ba)<1.5、m(B)<300×10-6]. With the formation change from old era to new era, the deposition of the ancient water media group gradually fades: during C2b, the value of paleosalinity from 0.70‰ to 2.63 ‰, during C2h, the value of paleosalinity from 0.33‰ to 2.64 ‰, during C2k, the value of paleosalinity from 1.13‰ to 2.64 ‰. The understanding plays a complementary role for sedimentary environment and tectonic setting of the study of the Late Carboniferous in Santanghu Basin, which has the great significance in Carboniferous oil and gas exploration.
