Abstract: Field work was carried out during May-Aug. of 1987 in Taiyuan of Shanxi province. According to the flying characters of Black Drongo, 6 types are devided (touring,expelling, feeding, material-bringing, food-bringing and random). The frequency of each flying type (freq/hr) varies in different breeding stages of this bird. The territory size is larggest in nest-building period and smallest in incubation period (2.44 and 0.70 ha respectively).Both sexes defend their common territory by singing, touring and expelling. 18 species of other birds are found in the territory, among which, 5 species are attacked by Black Drongo when they slowly close to it.