This survey had conducted for determining respiratory system disease and mortality trend of Ulaanbaatar city population and for developing evidence based recommendations. In accordance with the methodology we had done meta-analysis and statistical analysis on data 2004-2008. For the data analysis we used SPSS and parametric and non-parametric tests were used for determining disease changes and differences of seasonal, age and gender. In recent 5 years, in Ulaanbaatar, respiratory system disease cases are continuously leading 5 leading causes of disease. In 2008, respiratory system disease cases were 865.0 per 10000 populations and it is compare to 2004 increased by 10-30 percent. Children and women are more tend to attend to hospitals due to diseases cases. The survey also revealed that incidence of pneumonia (116.7-145.8 per 10000 populations) was the most visited case from other ICD10 causes of diseases.The mean age of mortality of respiratory system disease was 36.6±31.8 and the oldest age was 101 and the youngest was under 1 year old during 2004-2008 in Ulaanbaatar. During spring season, acute respiratory system disease, chronic bronchitis pneumonia and others respiratory system disease cases were more admitted from the respiratory system disease. Whereas, during autumn season, emphysema, during winter season bronchitis were the leading causes of respiratory system disease admission (x2=33.779, p=0.013).CONCLUSION: The statistics, 2004-2008 in Ulaanbaatar, were showing respiratory system disease trend constantly and continuously increasing. Age, gender and seasonal characteristics were signifi cantly correlated with the respiratory system disease. During these 5 years, 932 deaths were recorded and mean age of dying was 36.6±31.8.