Measures mainly based on the Coal to Gas Engineering (CTGE) for heating between 2012 and 2013 were taken to improve the air quality in Urumqi. In this paper, a comprehensive study was conducted to evaluate the effects of these measures on atmospheric environment in Urumqi by using the data of the concentrations of major air pollutants during wintertime of 2009~2014, the direct radiation, visibility, hazy days between 1993~2014. The results show that the concentrations of PM₁₀, SO₂ and NO₂ in Urumqi during the wintertime of 2013~2014 decline by 26.1%, 80.2% and 11.6% respectively compared to those in the wintertime of 2009~2011 which represent the concentrations before CTGE. The ratio of total water-soluble matter to PM_2.5 also decreases by 20.57%. The top three ions' concentrations in PM_2.5 are SO₄^2-, NH₄⁺ and NO₃^- before and after the CTGE. However, there is 50% decrease of the mass fractions of SO₄^2- and NH₄⁺ in PM_2.5 after the CTGE, and the mass fraction of NO₃^- in PM_2.5 remains unchanged. In the view of atmospheric physics, the total direct radiations during the wintertime in Urumqi increase after the CTGE and the value of 2013~2014 reaches up to the second peak for the past 23 years. There is a 5.7km increase for the wintertime visibility of 2013~2014 which is the maximum value since 1997. At the same time, there are 15days less for the wintertime hazy days of 2012~2013 compared to that of previous year which is a decrease of 50%. The results and analysis indicate that the CTGE for heating improved the atmospheric environment in Urumqi to a certain extent.