Abstract: The present invention relates to a method for improving a repebody protein comprising repeat modules and a nucleotide library encoding a repebody protein library for improving the repebody protein. More particularly, the present invention relates to a method for improving a repebody protein using a module evolution method of sequentially mutating repeat modules constituting the repebody protein, and a nucleotide library encoding a repebody protein library used to improve the protein. According to the module evolution method of the present invention, an improved repebody protein can be screened which has a high binding affinity and accordingly increased specificity and activity, and thus it is easy to express a repebody used as an inhibitor, a therapeutic agent, and an analysis means against a target substance.