In this study, the crystallinity index of CNCH2SO4 was lower than that of CNCCr(NO3)3, which could be ascribed to the reasonable explanation that the strong H2SO4 not only attacks the randomly-ordered structure in cellulose but also destroys the crystalline one during hydrolysis. For industrial uses, the addition of nanocellulose to a polymer matrix is one of the effective ways to reduce the oxygen transmission rate in packaging application; however, the slightly lower crystallinity of CNCH2SO4 might have a negative effect on its gas barrier property .