Abstract: According to a database of plot sampling on exotic harmful plants combined with the characteristics of exotic harmful plants, we introduced a new method in selecting and setting plots to determine the harmfulness of such plants. The determination content and calculation method of the diffusion ability of exotic harmful plants were determined by parameters of invasion environment conditions, the ability for sexual reproduction and asexual reproduction, and invasion status evaluation. We also calculated the invasion integrative analysis index of exotic harmful plants on the basis of the above results, to order to analyze the invasion status and development direction and determine integrative control of exotic harmful plants.

Key words: Harmful plant, Diffuse, Determination, Index