This study takes the central urban area of Alar City, Xinjiang Uygur Autonomous Region, as the research object. Stratifi ed sampling was used to conduct a survey of diff erent types of green space systems in the central urban area of Alar City. Subsequently, the biomass and material methods are used to calculate carbon sequestration and oxygen release for the urban green space, and annual carbon release and oxygen consumption for the central urban area, respectively. The carbon and oxygen balances of urban green spaces are obtained by comparing and calculating results. The results show that the total carbon sequestration and oxygen release of urban green spaces in the central urban area of Alar City are 96 600 tons; the city’s annual carbon emissions are 1.492 million tons; and the city’s annual oxygen consumption is 1.843 million tons. Thus, the carbon gap ratio for the central urban area of Alar City is 93.52%, and the oxygen gap ratio is 94.75%. Among them, the park green spaces and regional green spaces in Alar City have the strongest carbon sequestration capacity. Carbon release and oxygen consumption from industrial production and transportation account for the largest share. Based on calculations of the biomass heterologous growth equation for plants in the sample plot, it is concluded that the main factors aff ecting carbon sequestration and oxygen release in urban green spaces are plant species, plant combinations, and green space coverage rate. Based on this data, combined with the characteristics of arid urban green spaces, the amount of carbon emissions and carbon sinks in diff erent areas of the city, and using the theory of three-source green spaces, the central urban area of Alar is divided into three parts: carbon source green spaces, oxygen source green spaces, and near-source green spaces. Based on the layout, area size, and plant layers of the zonal green spaces, targeted optimization strategies are proposed. It not only provides a theoretical basis for enhancing the carbon sink capacity of green spaces in Alar City and optimizing their spatial patterns, but also off ers a reference for reducing emissions and increasing carbon sinks in green spaces of other drought-prone cities.