Global demand of energy is ever increasing and its resources due to extensive exploitation arc fastly diminishing. The days of inexpensive fossil energy are clearly numbered, the credibility of nuclear energy has fallen to new low, and fusion energy stands decades of more for practical realization. It is therefore imperative to turn to renewable raw materials for energy. At present there is worldwide interest in the process of converting photo synthetically derived substances into food. Chemicals and fuels. The imminent storage of fossil fuel has intensified the research for bioconversion of lignocelluosic material to fuels. The availability of solar energy needs to be linked up with cellulosic and hemicelluloses productivity. -glucosidase is one of the component enzymes of the cellulase complex and is widely distributed in nature. It catalyzes the hydrolysis of arly and alkyl glycosides as well as of cellobiose to glucose which is inhibitory to the endo and exo cellulases during cellulose hydrolysis. This book explain the production of Beta Glucosidase and its characterization.