为研究乌鲁木齐市大气环境中主要污染物PM_2.5的水溶性离子组分及其来源，2023年在城市中部布置采样点，通过膜采样的方式采集样品164个，按照相关测试标准测定PM_2.5的质量浓度及各水溶性离子组分浓度，并分析其来源。结果表明：（1） 采暖期PM_2.5质量浓度及各离子组分浓度均大于非采暖期。（2） 采暖期的离子总浓度是非采暖期的15.7倍，采（非）暖期离子总浓度分别占PM_2.5浓度的73.84%和26.26%，阴阳离子的比值（AE/CE）分别为0.914和0.600，说明PM_2.5化学性质呈碱性。（3） 硫氧化率（SOR）和氮氧化率（NOR）的年均值分别为0.43±0.30和0.15±0.13，说明采暖期气态前体物SO₂和NO₂在外部气象条件影响下二次转化的几率较大；$\mathrm{NH}_4^{+}$在采暖期主要以(NH₄)₂SO₄和NH₄NO₃的形式存在，在非采暖期则以NH₄NO₃的形式存在。（4） 主成分分析结果显示，采暖期污染物的主要来源于二次污染、工业生产和机动车尾气污染，其次为矿物粉尘和燃煤污染，累计贡献率达80.24%；非采暖期主要来源为扬尘和工业生产，其次为二次污染，最后为燃煤产生的污染，累计贡献率为86.34%。可以看出，不同时期PM_2.5中水溶性离子的来源存在较大的差异。

To investigate the water-soluble ion components and their sources in the major air pollutant PM_2.5 in atmospheric environment of Urumqi City, Xinjiang, China, sampling points were established in the city center in 2023. A total of 164 samples were collected using membrane sampling, and the mass concentration of PM_2.5 along with the concentration of various water-soluble ion components was measured following relevant testing standards. The sources of these components were also analyzed. The results indicate that: (1) The mass concentration of PM_2.5 and the concentration of ion components are higher during the heating period than that in the non-heating period. (2) The total ion concentration during the heating period is 15 times of the non-heating period, accounting for 73.84% and 26.26% of the PM_2.5 concentration, respectively. The anion-to-cation ratio (AE/CE) is 0.914 in the heating period and 0.600 in the non-heating period, indicating that the chemical properties of PM_2.5 tend to be alkaline. (3) The annual average sulfur oxidation ratio (SOR) and nitrogen oxidation ratio (NOR) are 0.43±0.30 and 0.15±0.13, respectively, suggesting a higher probability of secondary transformation pollution of gaseous precursors SO₂ and NO₂ during the heating period due to external meteorological conditions. $\mathrm{NH}_4^{+}$ primarily exists as (NH₄)₂SO₄ and NH₄NO₃ during the heating period, whereas in the non-heating period, it mainly exists as NH₄NO₃. (4) Principal component analysis indicates that during the heating period, the main sources of pollutants are secondary pollution, industrial production, and vehicle exhaust, followed by mineral dust and coal combustion, with a cumulative contribution rate of 80.24%. In the non-heating period, the primary sources are dust and industrial production, followed by secondary pollution and coal combustion, with a cumulative contribution rate of 86.34%. These findings demonstrate significant differences in the sources of water-soluble ions in PM_2.5 between the heating and non-heating periods.