【Objective】 Industrialization and urbanization have led to the emission of pollutants that can migrate and impact the functions of natural ecosystems. Therefore, it is important to understand the environmental behavior and fate of these pollutants as well as the factors influencing their ecotoxicity. This study aims to investigate the characteristics, sources, and environmental impact of polycyclic aromatic hydrocarbons (PAHs), a class of persistent organic pollutants, in the soil of typical forest and grassland ecosystems. 【Method】 Soil samples were collected from five typical forests and three typical grassland ecosystems in China. Soil physicochemical properties and PAH concentrations were measured, and the composition of PAHs was analyzed. The source apportionment of PAHs was carried out using diagnostic ratio methods and positive matrix factorization methods. 【Result】 The total PAH concentrations in the soil of grassland ecosystems ranged from 7.11 to 137.42 μg·kg^–¹, while in forest ecosystems, it ranged from 10.87 to 976.47 μg·kg^–1. The highest PAH level (208.82–976.47 μg·kg^–¹)was detected in Beijing Xishan Forest. Traffic emissions and coal combustion were the main sources of soil PAHs in forest ecosystems, contributing 41.6%–55.9% and 18.3%–31.8%, respectively. In grassland ecosystems, coal combustion was the dominant contributor to the content of PAHs in soil, accounting for 39.6%–50.2%, except in Zhangbei Bashang Grassland, where traffic emissions prevailed. Biomass combustion contributed more to grassland PAHs than to forest soils. 【Conclusion】 Although soil PAH levels in most natural ecosystems remain relatively low, the influence of human activities on PAH pollution in these ecosystems cannot be overlooked. Continuous efforts in pollutant emission reduction and environmental risk management are essential to protect the functions of natural ecosystems.