In Korea, the production of edible mushrooms was estimated to be 614,224 ton a year. In addition, yield of L. edodes (Shiitake mushroom) was estimated to be about 37,000 ton a year. The shiitake mushroom (Phyogo mushroom in Korea) has mainly been cultivated on tree logs. However, recently, bag cultivation using sawdust is rapidly increasing yearly due to its high yield and easily process and currently, the sawdust cultivation of Phyogo mushroom is approaching to almost 50% of the cultivation in Korea. The mushroom growers faced on disposal problem of the SMS and required the available measures to recycle it without environmental hazard. Spent mushroom substrate (SMS) is the post-harvest substrate and retains a variety of bioactive substances such as extracellular enzymes, antibiotics, secondary metabolites and carbohydrates produced during mycelium and fruiting body formation. Approximately, 5 kg of mushroom substrate are needed to produce 1 kg of mushroom, and consequently about 25 million tons of spent mushroom substrate (SMS) is produced each year in Korea. Because this massive amount of SMS is unsuitable for reuse in mushroom production, it is either used as garden fertilizer or deposited in landfills, which pollutes the environment. SMS can also be considered as an easily available source of active compounds to protect plants from fungal and bacterial infections, helping alleviate the waste disposal problem in the mushroom industry and creating an eco- friendly method to reduce plant pathogens. We describe extraction of lignocellulytic enzymes and antibacterial substance from SMSs of different edible mushrooms and their potential applications.