Abstract: In this study,the substitution degree of carboxymethyl konjac glucomannan nearest 0.1,0.2,0.3,0.4,0.5were selected to make films,the effect of the films conditions,including controlling the reaction time,temperature and sodium acetate content was examined by mechanical properties and characterization.Finally CK film optimum substitution degree was 0.2980,the TS and E of the modified KGM film were 21.43 k Pa and 32.1%,WVP and WVPR were 8.9 g·mm / m2d·k Pa and 11.4 g / h·m2,respectively,the POV was 15.81 meq /kg. The analysis of further validated the carboxymethylation reaction occurred on KGM by Fourier transform infrared and scanning electron microscopy and affect the microstructure of the film. Performance of the modified film had been greatly improved than non- carboxymethylation one. This research provided a technical basis for future study to edible konjac glucomannan film.