Abstract: Field investigation was made on ninety 2 m × 2 m sampling quadrats in Ligezhuang and Xiaocaocun villages of Miyun County, Beijing to analyze the population abundance, frequency, and importance value of invasive alien Solanum rostratum, as well as the species composition and flora characteristics of plant communities, aimed to assess the ecological state and ecological endangering risk of the invasive species based on its growth pattern, ecological advantage, and competitive aspects. In abundance, the S. rostratum was at the third position in Ligezhuang village (a total of 29 plant species), and at the fifth position in Xiaocaocun village (a total of 51 plant species); in frequency, the S. rostratum was at the first position both in Ligezhuang and in Xiaocaocun. The importance value indicated that the S. rostratum both in Ligezhuang and in Xiaocaocun had the greatest comprehensive adaptability. Accordingly, the invasion of S. rostratum in Beijing was still at a stage at which the damage was limited and locally, though the plant had overcome its growth bottleneck. Several species belonged to Poaceae, Compositae, and Moraceae had the potential acting as a counterweight to the progressive expansion of S. rostratum. For ecological intervention strategy,it could be established in the native species with some advantages and somehow predominated in adaptation to ecologically substitute or eradicate the invasion of S. rostratum before it became a single dominant species.

Key words: Growth irradiance, Photosynthetic characteristics, Protective enzymes, Tropical woody plant seedlings