Abstract: In order to have a water conservation mining under the weak ecological environment at the south border of Mu Us Desert, the paper analyzed the coal pi llar stability in the mines with the rib pillar mining method and the room and pillar mining method.The safety cofficient of the coal pillars was 1.12 and 0.89 individually and a long stability of the coal pillar could not be ensured.Based on the deposit conditions of Yangyu Mine at the border of the desert, a rib pillar backfill mining method was provided.The backfill material was the paste material with about 60% to 75% of the aeolian sand, the 28 days uniaxial compressive strength would be8~ 10 MPa a nd could meet the requirements of the backfill mining.The results showed that with the rib pillar mining with the aeolian sand backfill, the actual mining rate of the coal mining face in a mine could be improved from 44% to over 85%, the mine service life could be expanded of 89 years.The rib pillar mining with aeolian sand backilling C ould be effective to control the displacement and deformation of the overburden strata and to protect the integrality of the aquifer in the Quaternary System