The study conducted in Wangsan reservoir from July, 2006 to August, 2007 found that the observed birds were a total of 747 individuals in 46 species and they were 18 resident species, 15 summer migratory species, 9 winter migratory species, and 4 passage species. Although there were a large number of species and individuals from January to March, the species diversity index was low at 1.24~1.73, and the species diversity index was relatively high at 2.58~2.67 from May to July when the numbers of species and individuals were high. In this research, 5 endangered species were observed.