Abstract: Biomass and waste co-combustion has become the hot topic in scientific research and industries. It can not only increase the heating values of wastes, but also reduce air pollution and traffic safety threat resulted from biomass open burning. On the other hand, biomass co-combustion can cause series of environmental problems, such as slag, corrosion and increasing emission of PM10 and dioxin. This paper mainly focuses on the characteristics of biomass and environmental problems associated with biomass and waste co-combustion.