Abstract: There are 1 435 species and varieties, 682 genera and 166 families of vascular plants in Yixing,the south part of Jiangsu province, mo st of which are small families and small genera. The flora is dominated by the t emperate distribution types (55.84%). Based on species census, it is characteriz ed by the southern-Yangtze distribution type (40%), which comes to its north bo rder. The character of vascular-plant flora indicated that subtropical zone tra nsferred to warm temperate zone in Yixing and demonstrated it was right that the north border of evergreen broad-leaved forest in middle subtropical zone was p assed by Yili Mountain.