Abstract: The paper presents results of study on the breeding ecology of Black Grouse at Sai-Han-Ba mechanic forestry field,Weichang County,Hebei Province from 1990 to 1994.The usual breeding period of Black Grouse is between April and July.In the duration of the breeding period,the cock Black Grouse exhibits the behavior of the courtship display and has the enlargement of the red eyebrow as well as occupies the fixed lek.The average number of the cock Black Grouse at a lek is 7.5 individuals (range 3-14 ind).The courtship display peaks appeared twice a day time (4:00-7:00 and 16:30-19:00),but usally the former peak is more acute than the latter one.We had observed three kinds of the courtship displaying behavior and four kinds of displaying vocalization of the males,the former is body posture display,lutter-jumping and flutter-fly.Whereas the latter is calling,spacing,threat,and displaying vocalization.The mating behaviour was finished when the females entered the lek for 30-45 minutes.The nest is on the ground and the construction is very simple as well as built on hide sites.The materials of the nest is composed of some grasses,tiny branches and feathers etc.Each clutch has six to ten (average 8.9).The eggs average 35.33 g in weight,49.63×35.14 mm in size.We had recoreded the phenomenon of the supplement egg.The duration of incubation is about 28 days and only the female is responsible for incubating the egg.