Biomass is the most potential considering their quantitative availability. Prosopis juliflora a Mesquite is a shrub or small tree in the Fabaceae family. It is also one of the biomass which is available hundred hectares in our area. Casuarina equisetifolia is an evergreen shrubs trees growing to 35m tall. In order to characterize the physical and chemical properties of P.juliflora and C.equisetifolia as feed stocks for energy conversion process, we developed protocol. The particle size of both samples was found to be 8nm from X-ray diffraction (XRD) technique. Surface morphology of the samples was studied by scanning electron microscopy. Proximate, structural and elemental analyses showed that P.juliflora has lower moisture content and high fixed carbon indicates that it is appropriate to meet requirements of thermochemical process. Also, considered as one of the strengths of biomass utilization for energy purposes in terms of contribution to environmental protection, P.juliflora contains very low level of Mg and Ca (0.39% & 2.32% respectively). Higher proportion of carbon and lower proportion of oxygen content in P.juliflora leads to high calorific value 3891Kcal/kg.