This study investigated the green structure and airborne PM10 concentration (1.5 m above ground) in roadside buffer green zones to identify structural factors of buffer green that affect PM10 concentration. PM10 concentration measured in 10 buffer green zones was compared and analyzed with the PM10 concentration on the roadside, and the relative PM10 index (RPM10) was calculated. A positive value for RPM10 means a lower PM10 concentration of green space, while a negative value means a higher PM10 concentration of green space. The results of measuring PM10 concentration showed that the PM10 concentration on the green area was generally higher than on the roadside. The correlation analysis of green structure variables showed that RPM10 was significantly positively correlated with shrub layer coverage, total tree cover, and shrub layer volume per m2, while no significant correlation was confirmed with average tree height, bole height, planting density, tree layer coverage, and volume per m2. Moreover, RPM10 in areas where the space behind the buffer green area was blocked was lower than in areas where it was empty. The regression analysis results showed that RPM10 in areas where the space behind the buffer green area was blocked was lower than in areas where it was empty (B=-.123, P=.000) and that RPM10 increased as the shrub layer volume (B=.674, P=.004) and bole height (B=.072, P=.015) increased. The higher PM10 concentration measured in the buffer green zone is believed to be the result of PM10 being blocked and stagnant in the green zone. Stagnant PM10 is removed inside the green area, contributing to reducing external PM10 concentration. The analysis revealed that planting shrubs and arranging low bole height trees and sub-trees is advantageous in blocking the flow of fine particulate matter. These results can be considered for a vegetation strategy to reduce fine dust concentrations when establishing future roadside buffer green spaces, as well as urban park and green space plans.