Daily activity patterns and micro-variations in specific behaviors are essential for understanding how primates meet their energetic and/or nutritional requirements while dealing with environmental change. However, such data regarding the Assamese macaques living in limestone forests has yet to be obtained. This study focused on the daily activity patterns and temporal distribution of feeding behaviors of Assamese macaques at the Nonggang National Nature Reserve in southwest Guangxi, China, using an instantaneous scan sampling method. Our results indicated that the Assamese macaques included two feeding peaks and two resting peaks. However, the resting peaks in the fruit-rich season occurred at midday (10:00e12:00) and at dusk (17:00e19:00), whereas the resting peaks in the fruit lean season occurred in the morning (7:00e9:00) and at dusk (18:00e19:00). Meanwhile, the intervals between the feeding peaks in the fruit-lean season were shorter than in the fruit-rich season. Moreover, fruit consumption generally peaked during the morning (37%). The consumption of young leaves during the morning was lower than that in the afternoon, likely being attributed to their higher water content. The implication of the findings is that Assamese macaques not only adjust their daily activity patterns and feedings to cope with the seasonal and micro-variations in temperature and dietary requirements but also adapt to their particular environment.