Abstract: The study was carried out in the coast of Bohai Bay from March to May and from July to October in 1992 and 1993. Nine sample areas along the coast were investigated quantitatively during the migration season. A total of 38 species of migratory birds belong to Charadiiformes were observed and studied. The population density, diversity index and homogeneity index showed that the coast of Bohai Bay is an important place on the Flyway of waders, especially the birds in Charadiiformes, during the migration season. However, the difference of species, numbers, diversity index and homogeneity index between the oil contamination areas and non oil contamination areas indicated that oil contamination on the beach seriously interfered with the structures of the waders and their environment.