The Sambar deer (Rusa unicolor) is a national protected animal (Category II). From May 2016 to May 2017, we investigated the behaviors of sambar deer in the salt site and other habitats in the Anzi River Nature Reserve of Sichuan Province to study the species’ population structure, daily activity rhythm, and salt-licking behavior rhythm through infrared camera trapping. The infrared cameras were installed in 108 locations, resulting in 401 and 620 valid records collected in non-salt and natural salt sites respectively. The results indicated that the daily activity rhythm of sambar deer differed across four seasons. In spring, daily activity peaked in the evening during the hours of 17:00-20:00. In summer, the peaks of diurnal activity were not obvious. Sambar deer had only one activity peak in autumn, during the hours of 17:00-19:00. In winter, there were three peaks of daily activity, appearing during the hours of 8:00-10:00, 17:00-19:00, and 23:00-02:00 respectively. The peak of salt-licking behavior occurred during the hours of 22:00-04:00 at night, and there was no significant difference in salt-licking behavior rhythm between males and females (coefficient of overlapping Δ = 0.670). There are two categories of salt-licking behavior in sambar deer, licking alone or licking in groups, but licking alone occurred more frequently and comprised 57.6% of all salt-licking behavior. When licking in groups, the group size of sambar deer varied from 2 to 7, with the most common group size being 2, and comprised 21.5% of all salt-licking behavior. The female to male occurrence ratio (female and male) of sambar deer in valid photographs was 2.05:1 in non-salt licking sites and 2.66∶1 in salt licking sites,
indicating that female deer replenish salt more frequently than male deer. This study provides important scientific information for the management of this protected species in the nature reserve.