In this study, pollen grains were sampled by using a Lanzoni trap (Lanzoni VPPS 2000) in atmosphere of Bursa in 1999 and 2000. During two years, a total of 13,991 pollen grains/m(3) which belonged to 59 taxa and unidentified pollen grains were recorded. A total of 7,768 pollen grains were identified in 1999 and a total of 6,223 in 2000. From these taxa, 36 belong to arboreal and 23 taxa to non-arboreal plants. Total pollen grains consist of 78.61% arboreal, 20.37% non-arboreal plants and 1.03% unidentified pollen grains. In the region investigated, Pinus sp., Olea sp., Platanus sp., Gramineae, Cupressaceae/Taxaccae, Quercus sp., Acer sp., Morus sp. Xanthium sp., Castanea sp., Chenopodiaccae/Amaranthaceae, Corylus sp., Artemisia sp., Urtica sp. and Fraxinus sp. were responsible for the greatest amounts of pollen. During the study period the pollen concentration reached its highest level in April.