The efficiency and security of secure group communication are dependent on the group key manager (GKM), which manages the group keys and membership Although a GKM can employ any kind of group key management algorithm, we adopt the logical key hierarchy (LKH) in this paper for its efficiency and scalability LKH is a tree-based group key management algorithm and it is more efficient when the key tree is balanced However, only a few papers or documents have dealt with practical tree balancing techniques so far In this paper, we propose LKHTreeManager, an LKH key tree management algorithm that is efficient for a large and highly dynamic secure group The proposed technique efficiently manages the key tree by combining LKH and AVL (Adelson-Velskii and Landis) tree We show that LKHTreeManager reduces the membership processing time, as well as the number of key messages.