In this paper, we discuss current typical load balancing mechanisms, which can be divided as static or dynamic model. We also discuss their program-data model known as SPMD and MPMD. On this basis, because of our research work, we have built a new dynamic load-balancing model named as Periodical Load Rebalancing Model (PLRM) based on Java. We introduce agent technology to strengthen the host-host communication during re-balancing. As a result, the work of load balancing can be made more accurate and efficient. The final target of our work is to research how balancing should work in large-scale ubiquitous problem domain.