This paper discusses the efficiency of biomass energy management to clarify the impact of local resource management potential （LRMP） for large-scale urban area. When we consider the biomass cycle in the region, it is necessary the area concept including both urban and rural area. In addition, the networks for communities, cities, and regions are required in biomass management. These networks are considered social capital （SC）. In this study, SC was defined as flow of biomass management potential, and unused biomass were defined as stock of biomass management potential. Three kinds of biomass energy;agricultural and livestock biomass energy, forestry biomass and waste energy, were targeted. The size of 47 urban areas including rural area, Japan was estimated. Moreover, Data Envelopment Analysis （DEA） was used to analyze the efficiency of biomass energy management. Input data was the management factor including LRMP, and output data was the supply level of biomass energy. As a result, it was measured that the efficiency of biomass energy management was improved by the flow potential, and this improvement effect was greater than using stock potential. Finally, this paper suggested optimum area size and several recommendations of efficient biomass energy management using LRMP. JEL Classification:Q20, Q40, Q56, R58