Nanjing Botanical Garden Mem. Sun Yat.-Sen（NBG）is a semi-natural place located at the southern foot of Zhongshan Mountain, Nanjing, Jiangsu Province, China. It is rich in seed plants, both cultivated and wild, and contains a diversity of habitats within its 186 hm２ area. From April 2001 to November 2002, the plants which have invaded as weeds including woody weeds were surveyed in three hedge types of Euonymus japonicus（HEa）, Viburnum awabuki（HV）and Deutzia scabra （HD）respectively, and two hedge types of Buxus microphylla var. sinica （HBa, HBb）cultivated in different habitats in NBG. Another hedge type of Euonymus japonicus （HEb）was also investigated as a contrast cultivated in Nanjing Agricultural University （NAU）about 3 km away from NBG between April 2003 and November 2003. In total 1230 plant individuals were found to have invaded in these six hedge types, and they were identified as belonging to 70 species in 57 genera and 42 families. Among these plants, 1047 individuals of 55 species were adapted for bird seed dispersal based on previous research results of the seeds found in birds’ faeces and on the fruit characteristics, and 161 individuals of 10 species were adapted for wind seed dispersal according to their winged or plumed fruits or seeds, but the seed dispersal mode of the other 22 individuals of 5 species was uncertain.  Among the six hedge types，we found a significantly higher occurrence of bird-dispersed plant species than that of wind-dispersed species（t=5.086，df=10，p<0.0001）and of species with unknown dispersal mode（t=8.446，df=10，p<0.0001）.However, the difference of occurrence between wind-dispersed species and species of unknown dispersal mode was not significant（t=1.977，df=10，p=0.076）. The species number of bird-dispersed plants recorded in the five hedge types of NBG varied from 15 to 36, M±SD=25.6±8.1, and their Shannon-Wiener indices were between 2.151 and 2.917, M±SD=2.671±0.306. In contrast with NGB, only 12 species of bird-dispersed plants occurred in the hedge of NAU,with a lower Shannon-Wiener index of 1.679. This was largely due to a few critical limiting factors, such as lower species richness or poor seed sources，less abundant frugivorous birds, and much more frequent disturbances of human activities in its surrounding habitats.  As a result of cluster analysis of Bray-Curtis similarity of the invaded plant species adapted for bird seed dispersal, two hedge types of HBa and HEa were assorted into one group, three hedge types of HBb, HEb and HV were classified as another group, whereas the hedge of Deutzia scabra shared the least similarity with any of the other five hedge types attributed to its distinct habitat in the coniferous garden of NBG. The similarity of species composition of bird-dispersed plants between hedges was influenced to a large extent by the surrounding habitat characteristics, e.g. locality, seed source diversity, distances from seed sources, bird dispersal agent, and frequency of human disturbance, rather than simply dependent on the tree hedge species itself. Avian seed dispersal has enriched the species composition of each of the six hedge types consisting of just a single tree species. Although survival and colonization of the migrated plants will inevitably cause some influences to the aesthetic view of hedges, these invaded weeds or woody weeds could be managed and suppressed through regular artificial pruning and by eradication. The results indicate the important ecological significances of seed sources, bird seed dispersal, and shrub patches in promoting the successional development of woody vegetation.