To maintain Anammox biomass, different materials were used as carriers to immobilize Anammox sludge. The adsorptive property, anaerobic ammonia oxidation activity, and stability of the particles were evaluated. The results indicated waterborne polyurethane (WPU) was the most suitable immobilizing material. In a continuous flow experiment, we further investigated the resistance to impact load and the anaerobic ammonia oxidation activity by increasing the influent load. It was found that for WPUimmobilized particles, no effluent SS or particles fracture was observed during the 66-day operation, and the WPU-immobilized particles showed a strong capability to retain sludge and good stability in the long-term.