Abstract: From December 1999 to October 2000 , by analyzing bird diversities and component variation between seasons and habitat s , we surveyed bird species presence and abundance of three stage terraces on the Weihe Plain , Xianyang. According to the records , there are 124 species in this area , belonging to 15 Orders , 35 Families and 79 Genera. The result suggests that bird α-diversity is high in this area , as much as 3.28 , and is not the same between the terraces in different seasons. The higher β-diversity indices show that the species and component sare different among the habitats. The conclusion is that wetlands influence the bird diversities significantly and water is the dominant restriction factor to avian distribution and habitation in the Weihe Plain of China.