Abstract: To improve the flame retardancy of cellulose aerogels, graphene oxide (GO) nanosheets were employed as a flame retardant to prepare cellulose/GO composite aerogels by a simple freeze-drying method. Scanning electron microscopy implied that the optimum dosage of GO was 5 wt %in cellulose mucus, and GO was well dispersed in cellulose to form ordered three-dimensional porous aerogels under this condition. X-ray photoelectron spectrometry confirmed that the interaction between GO and cellulose was due to hydrogen bonding. The composite aerogels were well flame-retarded by GO at an optimum dosage of 5 wt %, and their combustion rate decreased to 0.57 mm/s from 5.67 mm/s of pure cellulose aerogel. Micro cone calorimetric resultsindicated that the peak heat release rate of the composite aerogelsdecreased by 57.7 % at the optimum dosage of GO compared to that of pure cellulose aerogel, suggesting a good flame-retardant effect. Theresidual char of the composite aerogels was found to become denser than that of cellulose aerogel, and their graphitization degree was enhanced due to the incorporation of GO nanosheets. In summary, the char yield of the composite aerogels was improved and their density and degree graphitization were enhanced due to the physical barrier effect and the catalytic charring capability of GO. As a result, the flame retardancy of the cellulose aerogels was improved effectively.