The aim of this study was to determine changes in cellulose acetate properties according to H2SO4 catalyst ratios. Cellulose acetate production was carried out at a concentration of 1, 2.5, 5 and 10% H2SO4 at 20 degrees C with traditional acetic acid method. Cellulose acetate samples were investigated FT_IR spectroscopy, x-ray diffraction method and Differential Scanning Calorimeter methods. Free acidity of cellulose acetate was 12.06% for 1% H2SO4 catalyst and 10.55% for 10% H2SO4 catalyst ratio in process, respectively. Degree of substitution of cellulose acetate was found higher for 10% H2SO4 catalyst than those of the other catalyst ratios. The glass-transition temperature (Tg) and the decomposition temperature (Td) for 1% H2SO4 catalyst in cellulose acetate production were determined 183.5 degrees C and 329.2 degrees C, respectively.