It is important to investigate bacterial air quality in urban forest parks because tree bacteriostasis practices are being increasingly advocated as measures to improve the air quality and public-health in urban green spaces around the world. The aim of the present study was to quantitatively investigate airborne bacterial concentration levels based on field measurements in every season in five selected forest communities and the uncovered space in an urban forest park, as well as the effects of several factors on the culturability of airborne bacteria. Results suggested that the airborne bacterial levels of all forest communities reached the clean air quality standard with regard to the airborne bacteria content, with the highest bacteria concentrations in the uncovered space (1658 ± 1298 CFU/m3), and the lowest in the mixed community (907 ± 567 CFU/m3). The temporal distribution analysis showed that the most airborne bacteria were concentrated in summer, as well as in the morning and afternoon. The bacteriostatic rates of the mixed community were significantly different with seasonal variation (p < 0.05). Spearman’s correlations revealed that the bacterial concentration was significantly positively correlated with the season, wind speed (WS), temperature (T), ultraviolet light (UV), negative air ion (NAI) and total suspended particles (TSP) (p<0.05), but significantly negatively correlated with the forest community type (p < 0.05). WS, UV, NAI, TSP and PM2.5 showed significant effect on airborne bacterial concentration in a multiple linear regression model (p < 0.05). Overall, the selection of tree species plays a key role in shaping the forest structure and improving air quality, and the urban forest highlights key priorities for future efforts towards a cleaner, healthier, and more diverse regional forest environment.