Chronic stress could affect behavior, physiology of animals and cause higher mortality, therefore it is important to understand the stressors of animals. It has been suggested that group-living primates may exhibit elevated stress level due to environmental change, food scarcity, as well as social relationship and interactions with their groupmates. The stress level is also related to age and sex of the animal. In this study, fecal cortisol of wild Taiwanese macaques(Macaca cyclopis)was analyzed to investigate how social dominance rank, kinship, reproductive status, and environmental factors affect the stress level of individuals in different age/sex classes. A total of 391 fresh fecal samples of known individuals in a macaque group were collected during January 2009 and January 2010 in the Fushan experimental forest, on which the cortisol levels were examined by the Chemiluminescent immunoassay(CLIA). The range of fecal cortisol appeared from 1.55 to 49.7ng/g(mean±sd:10±0.54ng/g, n=391). Fecal samples differing in the collecting time of the day and urine content were not significantly different in the cortisol level. No effect of age or sex on the fecal cortisol level was found. The fecal cortisol level appeared to show seasonal variation. It was significantly higher in spring and summer than in fall and winter. There was no significant association between the fecal cortisol level and the reproductive status, kinship, and social dominance rank in the Taiwanese macaque.