Abstract: This paper deals with a preliminary analysis on the cestodofauna of birds from Bai-Yang-Dien Lake,Hebei Province and Tai-Hu Lake,Jiangsu Province,China.Some conclusions are drawn as follows:1.There is a close relationship between the faunal distribution of the cestodes of birds and that of their hosts,since quite a number of cestodes show higher host-specificity.2.Kunds of hosts having nearer relation are parasitized by the same kinds of cestodes of kinds of cestodes having nearer relation.Based on this fact,we supposed that the host affinity can be demonstrated according to the hosts having same species of cestodes or having sibling species of cestodes.On the contrary,we can also infer the evolutionary advance of the cestodes form the evolution of their hosts accordingly.3.Comparisons are made of the cestodofauna of birds of the order Anseriformes collected from the two regiong-Bai-Yang-Dien Lake and Tai-Hu Lake.The results show thas kinds of cestodes of birds at the overwintering area (Tai-Hu Lake) are much more in number than those in the migratory area (Bai-Yang-Dien Lake).4.In Tai-Hu area there are 20 species of cestodes of birds,8 species of them are northern form,11 species are stochastical form,and one remains undecided.Ggographical distribution of the cestodes of birds in this area indicates that 4 species are local kinds,4 species are cosmopolitan,and one is widespread species in the Eastern Hemisphere.