Lignocellulosic biomass has been used as an alternative source to food crops that serve as feedstock for bioenergy production. The conversion of biomass to bioenergy required pretreatment process. Ionic liquids (ILs) have been recognized as promising solvents that are capable of solubilizing and separating components of lignocellulosic biomass. This research focuses on understanding how ILs affects the activity of cellulases in the enzymatic saccharification process. Sigmacell cellulose was used in the enzymatic saccharification process. Two different ILs were added in the enzymatic saccharification mixtures and the activity of a mixture of commercially available cellulases was measured using high-performance liquid chromatography (HPLC) to measure glucose release. Sulphate based ILs were more harmful for cellulase action than [EMIM][OAc]. [HBIM][HSO4] inactivated commercial cellulases (Celluclast (R)) and cellobiase (Novozyme188) in the enzymatic saccharification process. In this research, it was observed that the main factor that affects the activity of cellulase is pH.