The aim of the present work was focused on the cellulase production by Aspergillus niger using different substrates (i.e) rice bran, wheat bran, black gram bran, coconut oil cake, groundnut oil cake, and gingely oil cake. Solid state fermentation holds tremendous potentials for the production of the enzyme cellulase by Aspergillus niger. These agro industrial residues are cheap raw materials for cellulase production. Aspergillus niger was identified to be the best producer of cellulase. When A. niger was incubated for 6 days at 37°C it showed high yield of cellulase in groundnut oil cake substrate in solid state fermentation. Sucrose and nitrogen improved the yield in the same medium.