A DNA methylation editing kit comprises: (1) a fusion protein of inactivated CRISPR-associated endonuclease Cas9 (dCas9) having no nuclease activity and a tag peptide array in which plural tag peptides are linked by linkers, or an RNA or DNA coding therefor; (2) a fusion protein(s) of a tag peptide-binding portion and a methylase or demethylase, or an RNA(s) or DNA(s) coding therefor; and (3) a guide RNA(s) (gRNA(s)) comprising a sequence complementary to a DNA sequence within 1 kb of a desired site of methylation or demethylation, or a DNA(s) expressing the gRNA(s).