Abstract: In order to provide theoretical basis for the development and utilization of biomass energy, the author analyzed biomass accumulation, degradation and saccharification characteristics of Phragmites australis. With Phragmites australis as materials, samples were collected monthly to explore biomass changes and saccharification characteristics of Phragmites australis. The results show that: (1) the plant height had been on the rise since April, and it stopped growing in September, fresh weight and dry weight present similar change trend, (2) Phragmites australis fiber production was subsequently increasing up to 78.7% in September; (3) After alkaline hydrolysis and the processing of enzymolysis, the reducing sugar yield of Phragmites australis leaf and stem could reach 237.17 mg/g and 242.62 mg/g, respectively.