Bacteria belonging to genus Bacillus are rod shaped and can survive under unfavorable condition by transforming vegetative cells into spore. These spores can germinate and develop into vegetative cells which are capable of undergoing cell division. This represents the simplest model of cellular differentiation. It is now more or less established that the sporulation is triggered by a programmed activation of sporulation genes (spo). In this study an attempt have been made to clone GS gene by creating appropriate library and probe.