Every component of any bio-mass proves and inexhaustible resource of energy provided we generate the capacity of trap it. There are a number of options to convert biomass into useful energy. A system which provides both rich source of protein and efficient cattle feed is more feasible under rural conditions. Growing of mushroom based on agricultural residues is valuable option under rural conditions, but not much stress has been given to the technology. Keeping in view its simplicity and cost effectiveness this technology needs to be popularized on an extensive scale. Mushroom culture offers a low cost labor intensive technology for the bio conversion of straw into protein rich food, which is an important need of the country for meeting the requirement of the exponentially growing population. Modern mushroom culture produces more proteins per unit area of land than by any other form of agriculture. This also constitutes an excellent means of recycling many of the farm wastes. Since they are grown indoors no additional land is required for their culture. Their cultivation is labour intensive and can provide employment to both educated and illiterate prisons. Mushrooms represent the oldest microbial food, a delicacy of cuisine and the first solid state fermentation product. (jacket)