Random capture and indiscriminate killing are the main reasons for the decline. During the period of 1950, western China purchased 10000 pieces of rabbit hair and rhesus monkey hair every year. In some key counties in eastern Tibet, each county bought 500-700 pieces of rabbit hair in the middle and late period of 1970, while only a few dozen pieces were bought during 1980, which shows that the number of its wild population is decreasing year by year. Because the living areas of rabbits and monkeys are not suitable for human habitation, the loss of their habitats is not the main reason for their decline.