Provided are novel solubilized collagen fibers with which solubilized collagen can be obtained by instantaneous uniform dissolution in water at the time of use. The solubilized collagen fibers are formed from a solubilized collagen solid content of 66 to 87 wt %, buffer salt content of 2 to 6 wt %, water content of 10 to 22 wt %, and a residual hydrophilic organic solvent content of a trace amount of up to 6 wt % (totaling 100 wt %). The solubilized collagen fibers have an average fineness of 3 to 10 dtx, an isoionic point of 4.5 to 5.0, a water content of 10 to 22 wt %, and residual hydrophilic organic solvent content of a trace amount of up to 6.0 wt %. The solubilized collagen fibers are present uniformly in the direction of fiber length. The buffer salt is selected from sodium citrate, sodium lactate, and sodium phosphate.