Abstract: Based on the quantitive analysis of five pollutant contents in the leaf samples which were collected from the three ecological forests in Zhenhai district, Ningbo,Zhejiang province, this research is expected to provide experimental data for the evaluation on the effective of ecological forest and species chosen. The results showed that, as the distance between the ecological forest and the industry areas become shorter, the content of pollutants in plants and the ecological benefits of purifying the air become higher; that is, Haitian ecological forest belt >Zhenluo ecological forest belt>Xiongzhen ecological forest belt. The ecological benefits of the eight plants are ranked by DPS. From high to low, the sequence is populus sp,Taxodium ascendens,Viburnum odoratissimum, Hibiscus syriacus, Ligustrum lucidum, Cinnamonum camphora, Elaeocarpus balansae, Osmanthus fragrans.

Key words: ecological benefits, gray relation grades, ecological forest belts, ecological benefits, gray relation grades