The present study includes the optimization of dilute sulphuric acid pretreatment of peanut shells as substrate for the production of cellulose enzyme using Box-Bhenken design of Response Surface Methodology. The pretreatment of substrate was conducted through Box- Bhenken design of Response Surface Methodology. Three factors with three levels such as H2SO4 conc. (0.6, 0.8, 1%), substrate conc. (5, 10, 15%) and residence time (4, 6, 8h) were employed for pretreatment with and without autoclaving at 121oC for 15 min. The enzyme production was carried out in an Erlenmeyer flask of 250mL capacity using pretreated peanut shells as substrate by Bacillus subtilis K-18 in submerged fermentation at 50 °C for 24 h. Results revealed that acid pretreatment was found more effective for cellulase production as compared to thermochemical pretreatment. The maximum CMCase activity was 1.757 1U/ml/min under conditions of 0.6% acid concentration, 10% substrate concentration, and resident time of 4h. The maximum FPase activity was 2.015 1U/ml/min under conditions of 0.8% acid concentration, 10% substrate concentration, and time of 6h. This showed that peanut shells could successfully be used as substrate for cellulase production in submerged fermentation.