Badain Jaran desert lies in the northwest of Mongolia. In the eastern desert, the coexistense of lots of lakes surrounding big immovable sand dunes, the peculiar influences of wateriness inside the sand dunes and ascending springs in the lakes have been found. Similar conditions occur in its north and northwest areas. In this paper, combined with hydro chemistry factors, a method similarity priority ratio is firstly applied to analyze some water samples of different positions in Badert Jaran desert and its surrounding areas. And a result that it has a good hydraulic relation on the snow water of Qilian Mountain and lakes in the desert and ground water in some surrounding areas has been given.