Aims: This experiment purpose are finding that using biochar of reed plants (Phragmites autralis); it is a plant species grows a seasonal cycle, it also is a very high biomass in Mekong Delta (MD) of Vietnam. To evaluate fresh, dry biomass and made of reed plants biochar to use them provide bio-organic fertilizer for rice plant (ST 25) in experiment. Methods: To achieve this aims some experiments have done by methods in laboratory of The Forestry Institute of Southern Vietnam are contens follow as:(1) investtigating biomass of fresh, dry reed plants and made of biochar by use the local method; (2) analyse the chemical indicators in 3 different locations tis area on trunks, leaves, flowers in study area; (3) identify chemical indicators of peatland on 3 different locations of MD; (4) adsorption with pig urine and chemical fertilizer (nitrogen, phosphorus and potash) to see the retention off chemical coponents dispersed into the environment in the adsorbed biochar; (5) use the formulas of reed plant biochar mixed peat and mineral inorganic fertilizer. Results: The results showed: The reeds in 3 locations of MD can provide big amount of biomass to made of reed biochar fertilizer; reed biochar can adsorpted as ammonium, nitrate, nitrogen, phosphorus and kalium the pig urine and it also adsorpted inorganic fertilizer as nitrogen, phosphorus and Kalium. Thus it is possible to use for application treatment environment in the region polluted and planting local rice ST 25 in the experiment area in MD. Conclusions: Biomass and biochar of reed in MD are big amount for the material of environment treatment and agriculture fertilizer; in chemical indicators of trunks, leaves and flowers in locations have some indictors are diffrence and some are not differncecs; the chemical indicators of some location are not differences; the mixed biochar, peat and inorganic in formulas in 5 days and 10 days were not differences; biochar can adsorb some chemical components of pig urine and nitrogen, phosphorus and kalium fertilizer; biochar can mixed peat and inorganic mineral fertilizer to planting rice ST 25 in Mekong Delta.