Abstract:[Objective] To analyze the spatial and temporal pattern of PM 2.5 concentration and explore its correlation with land-use pattern in order to provide a basis for decision making in ecological protection and air pollution control.[Methods] Based on PM 2.5 concentration data as well as the land-use information in 2013, we divided the whole Nanjing City into 9 regions by means of Thiessen polygon method. We then systematically analyzed the temporal-spatial differentiation of PM 2.5 and its correlation with the variation of land-use pattern in a time-scale of year and season.[Results] In time scale, the concentration of PM 2.5 was the highest (129.93 μg/m3) in winter, and the lowest in summer (only 44.65 μg/m3). In spatial scale, according to the data of annual average PM 2.5 concentrations in each monitoring station, several sites such as Maigaoqiao and Ruijinlu had high PM 2.5 concentrations, reaching 78.90 and 78.56 μg/m3, while PM 2.5 concentrations in the Xianlin and Zhonghuamen Development Zone was the lowest with only 72.08 and 72.64 μg/m3. On the other hand, land-use patterns affected average PM 2.5 concentration, i. e., arable land, grassland, water and barren land, rural residential land were negatively correlated with PM 2.5, and water body has highest correlation with PM 2.5. In general, the landscape in terms of area, density, fragmentation and accumulation degree was the main factors affecting the PM 2.5 concentration.[Conclusion] PM 2.5 concentration showed an obvious spatial and temporal distribution pattern. The variation of land-use had important effects on PM 2.5 concentration.