The concentration of negative air ions was directly impacted by plant community. In order to analyze the negative air ions distribution characteristics and those influencing factors, the 8 different plant communities were chosen in Taiyuan University of Technology botany garden as research objects at April to December in 2022. And then the indicators, such as the content of negative air ions, air temperature, relative humidity, PM2.5 and PM10 were determined. As results, (1) The variation trends of negative air ions were different in the four seasons. In spring, the content of negative air ions showed an upward trend and had a largely rising range at 9:00 ~10:00 am and 17:00 ~ 18:00 pm. In summer, it firstly increased at forenoon, and then declined at noon, and increased again at afternoon; meanwhile, the highest value of the whole day was at 17:00 to 18:00. In fall, it first increased and then decreased, reaching the highest value at 10:00 ~ 12:00. In winter, there were no significantly changes. (2) The negative air ions concentration was higher in summer than that in spring and autumn. However, the plant communities with complex vegetation structure were higher than those with simple vegetation structure. Specifically, the two plant communities, S4 (Platycladus orientalis + Juglans regia + Prunus Cerasifera) and S7 (Crataegus Pinnatifida), showed higher levels of negative air ions concentration than others. (3) The correlation between negative air ions and meteorological factors were different among experimental plant communities. Generally, the negative air ions contents showed positive correlation with air temperature, and negative correlation with relative humidity, PM2.5 and PM10.