The mating system in Per(e) Davids deer (Elaphurusdavidianus) is polygamous.In breeding season,dominant stag holds a herd of hinds as its harem,and monopolizes the mating opportunities.During our observation of PereDavid s deer in the summer of 2010 and 2011,we found the behaviors varied among harem holders.We assumed that the harem size was a probable factor behind the variances and tested our hypothesis in four main behaviors: breeding,feeding,resting and locomotion.The results showed that,with harem size growing,time spent breeding,locomotion,and frequency of breeding behaviors (investigation,display,holding harem and conflict) in harem masters mcreased significantly,whereas time spent feeding and resting decreased comparably.Our result suggests harem masters assign their behavioral budgets according to their harem numbers,thus to realize the maximum yearly mating success.