This study was carried out to investigate whether biomass materials which were produced using unused sea algae can substitute the oil-based plastic packaging material or wood material applied in packaging container. Three processes were carried to produce the biodegradable Ulva board which involves refining, compression molding and drying, and increased a process of defibrating to produce the biodegradable Zostera board. Mechanical properties evaluation of produced biodegradable bio-board show the rupture stress of Ulva board in the range of 15.56MPa to 49.55MPa, which is 1.3~4.1 times stronger in comparison with that of polystyrene plastic material used for food containers. Producing process of Zostera board is an appropriate technique and economizing on the producing time. Therefore, it is technically possible and propelling the packaging material forward.