Ionic liquids (ILs) are of great interest as potential solvents for the production of fuels from lignocellulosic biomass which is a potential source of biofuels. To study the effects of pretreatment, 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) was used to pretreat woody plants, kempas (Koompassia malaccensis) and jelutong (Dyera costulata), and non-woody plants, kenaf (Hibiscus cannabinus) and rice husk (Oryza sativa) at 120°C for 24 h. Cellulose was regenerated by the addition of water. The cell wall composition and structure of the lignocellulosic biomasses before and after the ILs pretreatment were observed and characterized using field emission scanning electron microscopy (FESEM), attenuated total reflectance fourier transform infrared (ATR FT-IR) spectroscopy, and X-ray diffraction (XRD). After the pretreatment, enzymatic hydrolysis was carried out to identify the total reducing sugars (TRS) yields using dinitrosalicyclic acid (DNS) method. Regenerated lignocellulosic biomasses resulted in high TRS yields compared to their counter-parts which are in agreement with the findings of FESEM, ATR FT-IR and XRD that exhibited regenerated cellulose were less crystalline and more amorphous upon IL pretreatment. Therefore, kempas and jelutong can be alternate sources for the biofuels production.