The thesis is aimed to find out the performance of Arundo donax, Phragmites australis, Typha angustifolia, Typha latifolia on methane yield for biogas production and the influence of grinding and cutting to these 4 species. The anaerobic digestion results showed that Arundo donax is the most promising species to produce methane, which was 441 L/kg VS after pretreatment with grinding, 355 L/kg VS of cutting. Grinding significantly increased methane production compared to cutting for these wetland plants. The thesis also reviews the performance of 8 species on methane production, treated with different pretreatments. Phalaris arundinacea L. revealed the highest methane yield among the 8 species being reviewed. The sizes of plants after grinding or cutting have significant influences on methane production. Physical pretreatments are worth recommending for environmental benefits and excellent performance on methane yield. More attention ought to be put on techniques of grinding, not only the efficiency-increasing but also the cost-reducing. Moreover, a general evaluation ought to be performed on cost and environmental influences hence we could achieve both the economic and environmental profits from utilizing of different wetland plants.