The present invention relates to: a ketone compound having transglutaminase-inhibiting activity, which is represented by the following Formula 1, 2, or 3:wherein R1 is a substituted or unsubstituted aryl or heterocyclyl group, R2, R3, and R4 are hydrogen atoms, n is 2, X is halogen, R5 and R6 independently represent a hydrogen atom or a substituted or unsubstituted C1-C10 alkyl, aryl, or aralkyl group, wherein R5 and R6 are not hydrogen atoms at the same time, or R5 and R6 may be taken together to form a saturated or unsaturated and substituted or unsubstituted heterocyclyl group containing a nitrogen atom (N)； an inhibitor of protein crosslinking comprising the compound； and a composition for preventing or treating a protein-crosslinking causative disease, which comprises the compound or the protein crosslinking inhibitor.
