The study was conducted within the grant to the “Project of developing the recommendations for protecting the human health from the water pollutions, conducting the survey on the quality and composition of water used for the meals and household purposes in Ulaanbaatar city”. We collected 129 water saples from the 7 districts of the capital city. Only the Chingeltei district has been mentioned here. Results show that the wells which didn’t meet the drinking water standard MNS 0900:2018 of many previous study have been closed and connected to USUG. 44.44% of the total samples taken are very hard level that exceeded the related standard, calcium ion dominated in their hardness. it can be considered as a not human activity pollution, nature pollution. Regarding to bacteriological analysis, water of Tsetsenhuu kindergarten’s is contaminated with total coliforms.