In recent years there has been a spurt of interest in xylan degrading enzymes due to their applications in several industrial processes - paper and pulp industries, food and feed industries, biofuel industry, textile industry, chemical and pharmaceutical industry, brewing industry. waste management, fermentation substrate to produce enzymes and many more. Xylan is the principal type of hemicellulose. An enzymatic complex is responsible for the hydrolysis of xylan, but the main enzymes involved are enzymes produced by fungi, bacteria, yeast, algae, protozoans, and more. Microbial Xylanolytic Enzymes describes the enzyme structure and its interaction with plant cell walls, the properties and production of different enzymes and their application and the knowledge gathered on the hydrolysis mechanism of hemicellulose. The knowledge gathered about the hydrolysis mechanism of the hemicelluloses, especially xylans, has greatly promoted the rapid application of these enzymes in new areas.