Cellulose is the most common organic polymer. The enzyme cellulase may break it into smaller sugar components, such as glucose subunits, which can be utilized to make ethanol, organic acids, and other compounds. Cellulases are a set of enzymes that have applications in various industries, including food, textiles, pharmaceutical, detergent, biofuels, and paper, making them the third-largest industrial enzyme utilized worldwide with rising demand. Cellulolytic fungi were first screened by exposing them to Carboxyl Methyl Cellulose agar (CMC), a selective media for cellulolytic bacteria. Further testing can be done on Czapek-Dox agar medium supplemented with 1% CMC. The cellulase production was significantly improved by optimizing many parameters such as pH, temperature, and substrate concentration.