The future network architecture towards heterogeneous, it would be converged many different types of network, such as cellular network, femtocell network, ad-hoc network, MANET, VANET and wireless sensor network. With new network service type and service demanding are emerging, it would cause the huge number of mobile terminal accesses to network. Hence, it makes big trouble for managing mobility, and brings forward challenge.The handover is the most important part in the mobility management, because the handover is frequently occurred when UE is moving, hence the handover number directly affects the system performance, and network QoS. A sophisticated HO decision algorithm can improve the performance of system, although in current literature there are many HO decision algorithms proposed and every algo- rithm owns dramatical advantages, but they also have limitations or drawbacks. In this report, we will survey the HO decision algorithms, and summarise them. Based on some current algorithms propose a new HO decision algorithm.