Nanocellulosea - new generation of cellulose materials was prepared from acacia mangium wood pulp by hydrolysis method using H2SO4. Suspension was cleaned into neutral by centrifuge followed by ultrasonication tratment at room temperature for 2 hours. Effect of hydrolysis time and temperature were studied. With acid concentration of 60% (w/w) at 45oC for 60 minutes with ratio solid/solution of 1/10, The yield of nanocellulose was around 64%. Nanocellulose was characterized by X-ray diffraction (XRD), Scan electron microscopy (SEM) and Fourier Transform Infrared (FT-IR). Obtanied nanocellulose is cellulose nanocrystal (CNC) with dimentions of 20-30 nm x 100-300 nm and crystallinity index of 90%.