Natural disasters such as snow storms have far-reaching effects on variations in the habitat structure and ecological aspects of non-human primates.Yunnan snub-nosed monkeys (Rhinopithecus bieti)inhabit high-altitude forest and endure harsh winters.The effect of heavy snow-storms (January 19 to February 6,2008) on two large groups of R.bieti (Gehuaqing group and Xiangguqing group) inhabiting Samage Forest in Baimaxueshan Nature Reserve were detected.Data on habitat damage was collected in April and May 2008 via field line sampling.Our results showed that two juveniles in the Gehuaqing group and three juveniles in the Xiangguqing group were found deceased following the storms.The snow storms also destroyed many trees in the Samage Forest and consequently food availability for R.bieti was reduced.Forest structure might change in the following years after this storm due to impact on ranging paths,food availability,and predation avoidance of the monkey.Only juveniles died suggested these individuals were the most vulnerable among members at different ages in this monkey.The fact that R.bieti is well adapted to high altitude and strongly seasonal habitat might explain its resilience to heavy snow storms.