Plant communities are basic components of urban green spaces, which play potent role in regulating air particle levels. Submicron particles have serious negative effects on air visibility, environmental quality and human health. Understanding the regulation mechanism of plant communities on submicron particles may better facilitate the mitigation of submicron particles (PM₁) pollution through the construction of urban green spaces. Based on field investigations, differences in the daily PM₁ level among eight plant community types were quantitatively analyzed, and correlations between daily PM₁ and various canopy parameters, including canopy density (CD), canopy porosity (CP), leaf area index (LAI) and sky view factor (SVF) were further established to detect critical thresholds. Results shows that plant community has a certain effect on reducing submicron particles, but there is no significant difference in daily PM₁ level among different community types in summer. Among the eight plant community types, mixed trees and grasses type may most effectively reduce PM₁, followed by broad-leafed trees, shrubs and grasses type, while conifer shrubs and grasses type has the weakest effect. The responses of daily PM₁ to various canopy characteristics are complicated, featuring non-linear relationships with critical thresholds. Plant communities with CD greater than 75% and CP less than 55% have outstanding effects on reducing submicron particles.