Residual lignocellulosics left to decay in fields and forest has a huge potential to serve as a low cost feedstock for production of bioethanol. In Indian subcontinent Ricinus communis is a major lignocellulosics growing in arid conditions containing 42% cellulose and 19.8% lignin. In the present study, Response Surface Methodology (RSM) based on Central Composite Design (CCD) has been used to explore the effects of pH, temperature, solid to liquid ratio (w/v), enzyme concentration and incubation time on enzymatic depolymerization of R. communis. The maximum delignification obtained was 85.69%. In case of lignified R. communis the optimum reducing sugar produced was about 288.83 mg/g dry substrate, whereas, in case of delignified R. communis the optimum reducing sugar produced was about 775.17 mg/g dry delignified substrate. After delignification reducing sugar yield was increased to about 2.68 fold. (C) 2011 Elsevier Ltd. All rights reserved.