This study aims to extract the cellulose fiber from banana pseudo stem (BS) and banana peduncle (BP) by using chemical extraction method. An optimization of acid hydrolysis is conducted using Design of Experiment (DOE) through Central Composite Design (CCD) to optimize the operating parameters such as concentration of sulphuric acid ( ), temperature and reaction time involved. The structural morphology, functional group, crystallinity and thermal stability of cellulose fiber (untreated and treated BS and BP) were characterized using Scanning Electron Microscopy (SEM), Fourier Transform Infra-Red Spectroscopy (FTIR), X-ray Diffraction (XRD) and Thermogravimetric Analysis (TGA) respectively. The optimum parameter for both BS and BP were found to be 5 mol/L of at 30 ºC for 60 minutes. Sample of characterizations indicated that the cellulose contents were improved through several chemical treatments where the hemicellulose and lignin were successfully removed. The yield of purified BS and BP cellulose fiber content after acid hydrolysis process were 88 % and 95 % respectively.