At present, air pollution has become the main problem in many developed and developing countries. Especially, in Ulaanbaatar city of Mongolia, it has become one of the most tackled issues of every citizen living in the capital city. The aim of this study is to highlight the trend of air pollution and pollution sources in the Mongolian capital and conduct some air pollution analyses. Overall, the study indicates that the air pollution in Ulaanbaatar city is a very serious problem and for its reduction, rapid and thorough measures should be taken.