Abstract: This paper presents rsults of our studies on the breeding ecology of Lady Amhersts Pheasant (Chrysolophus amherstiae) in Gulü (Eastern longitude 102°30′;Northern latitude 25°20′),western mountains of Kunming,middle part ot Yunnan Province.Surveys in sample plots shows that the density of breeding male pheasants in secondary forest of pine (Pinus armandii) is the lowest (See Table 1).The density of breeding males in deciduous secondary forest and in bush and coniferous-evergreen broadleaf secondary forest is not different.The reason relative to the difference is secondary forest of pine with a few of plant species and short age of food.Meanwhile,concealments are poor in secondary forests of pinc,so males are easily found by hunters and killed.The density of breeding female pheasants in secondary forest of pine is still lower.The reasonis is as indicated above.But the density of females in sample plot no.It is not different from the density of secondary forest of pine.The cause is that local people often fell trees and herd goats and cattle in sample plot no.When we were surveying population of females.Perhaps,the economic activties disturbed some females to move other forest.The density does not include males which do not occupy territory and females which do not breed,so it is only the density of breeding pheasants.Cocks begin to take territory in late of March.Accoding to observation of territory on 9 cocks,each cocks average territory is 0.076 km2 in the breeding season.There are 2-3 hens in each cocks territory.It is polygynous.Cock display takes place on a small open area in forest.It is typical lateral display and is similar to Golden Pheasant (Chrysolophus pictus).Females begin laying eggs in the middle of April.Six nests were found.All of which were built on land in thickets or under withered branches.The nests are very simple,a round shallow pit with dead leave and a few of feathers.The size of the nests and eggs in each cluth see Table 4.The eggs average 29.8 (26-32)g.In weights;45.4×34.6(43×33-46.2×35.3) mm in size.It is buff or white in color.Only the female takes responsibility for incubating the eggs.The weights of the eggs of no.5 nest were measured during the incubation period.Weight of eggs at the beginning was 29.8 g.,on eleventh,sixteenth,twenty-first days,they are 27.8 g.,26.3 g..and 24.8 g.Decrease progressively percentage of loss of eggs average weigh is 6.7%,11.5% and 16.5%,the duration of incubation is about 24 days.Chickens which just hatched stayed in the nest for several hours,then the female led them go off to look for food and did not go back to the nest again.After hatching,the female and young roost in dense bush at night.When the young can flight,they perch on trees at night.The young diets mainly consistes of fruits of Rubus spp.,Coria sinica,Vaccinium spregelii,etc.In the incubation period,we observed Red-billed Blue Magpic (Cissa erythrorhyncha) stole eggs when the hen was out of the nest.