Abstract: Avatar migration which changes the resident server of an avatar is an important issue in distributed virtual environment. Existing methods for multi-server DVE (distributed virtual environment) systems mainly conduct avatar migration according to the relationship between the avatars movement and servers region buffer, and the region buffers are fixed. However, regions are often regulated to balance the load in the latest multi-server DVE technologies. Then affected avatars have to migrate during the period of region regulation. This avatar migration of dynamic region buffer needs further study. An avatar migration mechanism based on cell buffer is proposed in this paper, where each region buffer is composed of a group of cells. Both cell and avatar are assigned to some status. Avatar migration is induced by two kinds, either avatar movement or region regulation. The mechanism abstracts the two kinds into a process of four critical conditions of status migration. Migration operations are devised on the status of avatar and the cell it resides on. In this way, many avatars can migrate concurrently with efficiency. The attribute update request of an avatar is only put in its region servers charge, which guarantees the status consistency. Experiments show that the mechanism can support concurrent migration efficiently, adding a low communication cost.