Abstract: The Biological diversity investigation in Anji County of Zhejiang Province has made a comparison between the agriculture based Yushanwu Village and industry dominated Beicun Village.The results of the comparison showed the number and amount of the water invertebrates species found in paddy fields,irrigation canals and ditches,and the natural enemies species existed in paddy fields in December were all higher in Yushanwu Village than that of those in Beicun Village.The number and Amount of natural enemy species (in October) and weed species of Beicun Village were higher than that of those in Yushanwu Village.It could be concluded that the number and amount of animal and plant species in paddy field ecosystem are closely related to the agricultural ecological environment and to the application rate of chemical fertilizers, pesticides and herbicides.