In our study, we performed quantitative proteomics and Kla PTM analysis to investigate the alterations in protein lysine lactylation in a mouse model of cardiac hypertrophy. The results identified 159 Kla-modified sites across 80 proteins, with 72 proteins showing increased Kla levels in hypertrophic hearts. These modifications were primarily localized in mitochondrial and sarcomeric proteins, highlighting their roles in energy metabolism and cardiac remodeling.