Abstract: To investigate the spatiotemporal distribution characteristics of negative air ion concentration in urban forests in subtropical regions and its relationship with meteorological factors, this study took urban forests in different areas of Longyan City, Fujian Province as the research object.Based on continuous monitoring data of negative air ions from 2020 to 2022,the spatiotemporal distribution characteristics of negative air ion concentration and its correlation with meteorological factors were analyzed.The results showed that the negative air ion concentration in urban forests of Longyan exhibited significant spatial heterogeneity, with the highest average concentration in exurban forests(2516 ions·cm^-3),followed by suburban forests(1989 ions·cm^-3),and the lowest in central urban areas(1455 ions·cm^-3).The monthly peak dynamics of negative air ion concentration varied across different regions: the peak occurred in January in central urban areas, in February in suburban forests, and in November in exurban forests.In terms of diurnal variation, the peak time delayed along the urbanization gradient: the peak appeared at 12∶00 in central urban areas, delayed to 14∶00 in suburban forests, and further delayed to 21∶00 in exurban forests.Pearson correlation analysis indicated that in suburban forests, negative air ion concentration was significantly positively correlated with humidity（r = 0.431）.In exurban forests, it was significantly positively correlated with both rainfall（r = 0.470）and humidity（r = 0.523）（P ＜ 0.01）.However, no significant correlation was found between negative air ion concentration and meteorological factors in central urban areas.