The granularity levels of blast furnace dust eliminated and environment ash were measured and particle size distribution was gained with laser particle size analyzer. By chemical analysis methods， the contents of Na₂O, K₂O and other non-ferrous metal oxide， Zn、As、Pb and Sn in gravity ash， whirlwind ash， bag ash and environment ash were analyzed. The distribution of harmful elements in dust eliminated and environment ash is researched. Results show that: the gravity ash granularity is the biggest in which harmful elements content is the least， taking up only 1.94%； the bag ash granularity is the smallest， in which harmful elements content takes up the most percentage， about 15.79%. Compared with all the ash eliminated， the environment ash granularity turns out to be the smallest， with harmful elements content being 1.02%， which shows that the smaller the granularity of blast furnace gas dust eliminated is， the more harmful elements it contains. Removal of the harmful elements in the bag ash is one of the important methods for disposal and recycling of the harmful elements.