Cellulase enzyme has the ability to hydrolyze the cellulosic materials and play a vital role in the field of Genetic Engineering and Biotechnology. The current research enzyme producing strain was isolated from the gut of the Silver fish. The organism was confirmed as Cellulomonas cellulans. The enzyme was produced using CDA broth and the production of cellulase was about 2.5ml/100ml broth. Further assay of enzyme was done and the enzyme assay was found to be 0.160 mg glucose/min/mg of protein. The molecular weight of the enzyme was determined by SDS PAGE method, the molecular weight of cellulase enzyme was found to be 35 KD, 18KD, 12 KD.