The purpose of the present invention is to provide a composition for producing fibers, to provide fibers that are obtained by spinning the composition, and to provide a cell culture scaffold material that uses the fibers. The composition is for the production of fibers that retain organic solvent resistance and is suitable for fixing a substance that is effective in the adhesion, proliferation, differentiation, etc. of cells. A composition for producing fibers, the composition containing (A) a macromolecular compound that includes a unit structure represented by general formula (1) and a unit structure represented by general formula (2), (B) a cross-linking agent, (C) an acid compound, and (D) a solvent. [The notation used in formulas (1) and (2) is as described in the description.]