To reduce traffic between multiple servers in a presence system and improve the performance of the presence system, a method and device is provided for user-management in a presence system, and a presence system. The presence system comprises multiple presence servers communicating through a network, and said device for user-management comprises a combining means for combining multiple user sets among which there are the greatest correlations into a user set to be allocated; and an allocating means for allocating said user set to be allocated to one presence server which can contain said user set to be allocated. Through allocating multiple user sets among which there are the greatest correlations to a same presence server, communications among users in the user set are performed within a same presence server, reducing occupations for network resources and improving performance of the presence system.