Bioenergy can be obtained from various forms of biomass such as agricultural, food processing, and municipal wastes. Recently, its importance is recognized more seriously because of its positive impacts on economic and stable energy supply and environmental sustainability. Despite its advantages, bioenergy has not been used as much as it was expected, nor has it been developed to the level of attractive commercialization in energy market. The main reasons for the sluggish progress have been analyzed by comparing the bioenergy policies in Korea and U.S.A. Both Korea and U.S. governments have recognized the importance of bioenergy and put in various efforts to promote the use of bioenergy. Both governments have legislated alternative energy promotion plans that support R&D, tax reduction, rewards, and low interest loans. However, it is suggested that the bioenergy policy and plan juxtapose the financial supports (R&D, tax exemption, low interest loan, education, etc.) with strong mandates and obligations. Although imposing strong mandates prerequisites the economically attractive and feasible technologies, it can motivate and speed up more effective technology development, in turn. In addition, the bioenergy R&D support must include studies on commercialization and marketing as well as process development. R&D on the socioeconomic effects of bioenergy should also be supported. Lastly, decision making processes for the bioenergy policy, and for alternative energy overall, must include environmental agencies for taking advantage of environmental benefits of bioenergy.