Fine particulate matter (PM_2.5) has become a significant issue of ecological environment. However, few studies have explored the vertical distribution of PM_2.5 in cities. The objectives of this paper are to reveal the vertical distribution regular pattern of PM_2.5 over urban underlying surfaces near the ground with a hexacopter-type unmanned aerial vehicle (UAV) in winter. Results showed that the maximum vertical gradient of PM_2.5 near the ground was typically the greatest in the morning as the stable atmospheric conditions. Moreover, regression model illustrated that relative humidity had the greatest impact on the vertical profile of PM_2.5 compared to air temperature and altitude as hygroscopic of PM_2.5 aerosols. Curve model shown that vertical profile of PM_2.5 over the surfaces of water and green space first increased slowly and then declined, besides, the highest concentration inflection of PM_2.5 above the water body (23.7 m) is higher than the green space (14.3 m). Thus, suggesting residents living vertical of 10–30 m from the ground around large water bodies and green spaces should not open windows for ventilation in the morning. Therefore, this study provides insights into the vertical distributions of PM_2.5 over different underlying surfaces and should be of reference value to urban planners for designing urban spaces to optimize atmosphere environment to provide a healthy living environment.

细颗粒物（PM _2.5）已成为生态环境的重要问题。但是，很少有研究探索城市中PM _2.5的垂直分布。本文的目的是揭示冬季使用六旋翼型无人飞行器（UAV）在靠近地面的城市地下表面上PM _2.5的垂直分布规律。结果表明，作为稳定的大气条件，靠近地面的PM _2.5的最大垂直梯度通常在早晨最大。此外，回归模型表明，相对于空气温度和海拔高度，相对湿度对PM _2.5的垂直分布影响最大，因为PM具有吸湿性_2.5气溶胶。曲线模型表明，PM _2.5在水和绿地表面的垂直剖面首先缓慢增加然后下降，此外，水体上方PM _2.5的最高浓度拐点（23.7 m）高于绿地（14.3 m） ）。因此，建议居民在离大型水体和绿地不远的地面垂直生活10–30 m，早上不应该打开通风窗。因此，本研究提供了对PM _2.5在不同下表面的垂直分布的见解，对于城市规划者设计城市空间以优化大气环境以提供健康的居住环境具有参考价值。