Abstract: A method for preparing carbamated cellulose fibers applicable to mass production is provided. The method for preparing carbamated cellulose fibers in which hydroxyl groups of cellulose fibers have partially or fully been modified with carbamate groups, includes heating a pulp sheet which has been formed into a strip shape by subjecting a raw material pulp to papermaking and contains urea or a derivative thereof, between a pair of rolls while passing therebetween, to cause the modification.

Abstract: A fibrous cellulose-containing material having excellent dispersibility even when dried, a method for preparing the same, and a fibrous cellulose composite resin having excellent strength. The fibrous cellulose-containing material is for addition to resin, and contains fibrous cellulose having an average fiber width of 0.1 to 19 ?m and having hydroxyl groups partially or fully substituted with carbamate groups, and interactive powder that is interactive with the fibrous cellulose. The fibrous cellulose composite resin contains the fibrous cellulose-containing material as fibrous cellulose. The method for preparing a fibrous cellulose-containing material includes defibrating fibrous cellulose having hydroxyl groups partially or fully substituted with carbamate groups to have an average fiber width of 0.1 to 19 ?m, and mixing with interactive powder that is interactive with the fibrous cellulose to obtain a mixed liquid, and drying the mixed liquid.