Abstract: This article summarized the significant contribution of biomass to the world's energy supply and the great interest gained by using biomass world-widely. The main biomass energy conversion routes, i.e. modern biomass energy conversion technologies were discussed in details. Economic benefits were analyzed from the aspects of plantation biomass costs and electrical power generation costs. Environmental impacts of biomass energy systems were discussed from the aspects of conversion of water and soil, agro-ecology, and biodiversity. Finally, the barriers of bio-energy development and strategies were concluded.