Native cellulose samples with high crystallinity were pyrolyzed up to above 2000 C and the resulting carbon structures were examined. The drying method for water-swollen or water-suspended cellulose prior to pryrolysis was found to significantly affect preservation of the large surface areas of the original cellulose; i.e., solvent exchange drying (water-ethanol-t-butyl alcohol) of hydrogels and rapid-freeze drying of water suspended particles by spraying onto a cooled copper plate gave surface area of cellulose of 60-120 m(2)/g, about twice of those by ordinary freeze dyring. The carbons derived from these materials had nearly the same surface area as the starting cellulose and maintained the nanofibrillar morphology.