A fine cellulose fiber composite containing fine cellulose fibers and a polymer having an ethylene oxide/propylene oxide (EO/PO) copolymer moiety or a propylene oxide (PO) polymer moiety, the fine cellulose fibers being connected with the polymer via an amide bond. The fine cellulose fiber composite of the present invention has high dispersibility in the resin and can exhibit an effect of increasing strength, so that the fine cellulose fiber composite is suitably used as various fillers, and the like. Also, the resin composition of the present invention containing a dispersion of the fine cellulose fiber composite can be suitably used in various industrial applications such as daily sundries, household electric appliance parts, wrapping materials for household electric appliance parts, and automobile parts.