Abstract:Propulation trends of wild cat species were estimated based on the data collected from 30 transect lines oin each winter of 1985 to 2009 and from interviewing the local people in Changbai Mountain Nature Reserve and its surrounding area. Previous studies have recorded the tracks of four cats, Eurasian Lynx(Felis lynx), Leopard Cat (F.benglaensis), Siberian Tiger(Panthera tigris), and Amour Leopard(P.pardus) in the study area. However, only Lynx and Leopard cat were found in our filed survey. Transect lines with tracks of Eurasian Lynx only accounted 3.09%±2.30% of the total transect surveys conducted, and the encounter rate was 0.010±0.007 ind/km transect in average. The tracks of Leopared Cat were recorded in 7.66%±6.19% of the total transects surveyed with a encounter rate of 0.03±0.02 ind/km, respectively. Total of 13 killings on Siberian Tigers and 2 killings on Amure Leopards were reported by the local people in the region of Changbai Mountain Naure Reserve and surrounding area with 6 000 km2 in size during 1960s to 1980s. The historical density of Siberian Tigers and Amur Lecopards per 100 km2 were estimated 0.22 and 0.03 individuals, respectively. The home range of Siberian Tigers was estimated 560 km2 based on the area size of 13 killings occurred. The population density of Eurasian Lynxes and Leopard casts decreased significantly in recent years, the two cat species were endangrered in the study area. Habitat destruction, lower prey density and hunting are the three major reasons for the cat populations decline in the study area.