中文摘要：

Phyto-groups on 5 remained city wall sections of the Ming Dynasty in Nanjing City was investigated through on-the-spot survey,99 species of 93 genera,60 families were found,and species of Asteraceae and Poaceae accounted for the largest ratio.Plants on the city wall are characterized by strong drought resistance and precocity,their seeds can grow out of the wall cracks,and roots secrete acidoid and obtain nutrients from wall bricks.Plants on different wall sections are different,and human interventions influence phyto-groups on the city wall greatly.On this basis,it was concluded that plants had negative influence on city wall,especially plant roots destroyed the wall seriously.Corresponding researches were carried out and prevention suggestions proposed to provide scientific support for the protection of ancient city walls in Nanjing City.