The role of modification of histone lysine 2-hydroxyisobutyrylation in atrial fibrillation is unclear and we hence explored the role of 2-hydroxyisobutyrylation in atrial fibrillation. Tandem Mass Tag proteomics method and other verification technologies in tissues and cells identified the protein profiles and the regulation of 2-hydroxyisobutyrylation sites. The atrial tissue of the patients with atrial fibrillation has significant differences in modification of 2-hydroxyisobutyrylation compared to that in sinus rhythm.