Abstract: Forest_herb ecosystem, Eucommia ulmoides intercropping with Trifolium pratense and T. repense, E. ulmoides intercropping with Lolium perene, E. ulmoides and Artemisia spp. mixed community, was investigated and the relationship between height growth rate of tree individual and interference intensity of neighbourhood herbs was analysed by using the improved model of neighbourhood interference. The results showed that: 1. Trifolium spp. increased the growth rate of E. ulmoides (positive effect), while L. perene and Artemisia spp. reduced the growth rate of E. ulmoides (negative effect); 2.interference intensity was in proportion to quantitative characters, such as coverage, weight of biomass and height of herbs, and in inverse proportion to the size of subject tree when the effect of neighbourhood interference was negative, and in proportion to the size of subject tree when the effect was positive; 3.the effect models of neighbourhood interference accounted for 25%70% of the variation in the height gro