Abstract: Taking 6 typical greening tree species in Kunming as the research object. The dust retention of the leaves was determined by washing and filtering method, and the morphological structure of the leaves was observed by S-3000N scanning electron microscopy. Results show that there are significant differences in dust retention among different tree species. The amount of dust in the unit area of 6 tree species from large to small is Osmanthus fragrans > Magnolia grandiflora > Rhododendron pulchrum > Loropetalum chinense > Platanus acerifolia > Cinnamomum camphora. The dust retention ability of the same tree species is different in the 4 quarters of a year, and the dust retention in autumn and winter are the largest. Leaf surface fold and rough, gap width and distribution is irregular, moderate opening stomatal density and strongest dust detentions of O. fragrans, the average annual dust retention is 4.532 5 g/m². Dust retention ability of M. grandiflora with a large number of winding villi is the 2nd, the average annual dust retention is 2.633 6 g/m². C. camphora is the worst with wide gully, fewer stomata and more closed and fluffy, the average annual dust retention is 0.727 5 g/m². Therefore, when selecting tree species for urban greening, choosing tree species whose leaf shape is beneficial to dust retention can improve the effect of the plant to purify the atmosphere.