Abstract: Seven different plant communities and control sites（CK） in Hohhot Arboretum were used as test materials, positive and negative air ions concentrations, meteorological factors such as temperature, humidity, wind speed, and dew point temperature in different plant communities and control sites were monitored simultaneously, the spatial and temporal distribution patterns of air negative ions concentration in different plant communities in Hohhot Arboretum in summer and its relationship with meteorological factors were studied, and the air quality conditions at different monitoring points were evaluated, in order to provide reference for the design of urban green space and the construction of urban forest recreation activities.The results showed that the daily trend of negative air ions concentration in each community was generally ‘V’ shaped.In other words, there was a peak at 08:00 and 18:00,and a minimum at 12:00.The daily average values of negative ion concentration at each monitoring site were, in descending order, such as Pinus sylvestris community（S1）,Syringa oblata community（S2）,Acer mono Maxim-Acer truncatum Bunge community（S4）,Pinus tabulaeformis-Syringa oblate-Ribes nigrum community（S5）,Pinus tabulaeformis-Syringa oblate-Prunus triloba community（S7）,Pinus tabulaeformis community（S3）,Picea dietr-Prunus triloba-Sambucus williamsii（S6）,and hard square（CK）.The concentration of negative ions in the air was extremely significantly or significantly correlated with temperature, wind speed, dew point temperature, and relative humidity, and had no significant correlation with atmospheric pressure.The air quality classes for each plant community in the arboretum were permissible and health concentrations, and the daily trends were generally consistent with the daily changes in negative air ions.