Coordinated response of the heart to physiological stressors (including stress overload, ischemia, hypothyroidism, and metabolic signals) is a hallmark of heart disease. However, effective treatment and its molecular targets are unknown. Although Maslinic Acid (MA) has been shown to inhibit inflammatory responses with strong anti-tumor, anti-bacterial, and antioxidant effects, information on its role and underlying mechanism in cardiac hypertrophy are scanty. The present study revealed that 10-103 μg/ml MA treatment significantly inhibited Ang-II induced hypertrophy in NMCMs and the dosage did not influence the cell viability of H9C2 and NCMCs. Moreover, the anti-hypertrophy effect of MA (30 mg/kg·day) was verified in the TAC-induced hypertrophy mouse model in vivo. Further analysis showed that MA administration decreased the total RNA m6A methylation and METTL3 levels in Ang-II treated NMCMs and TAC stressed hearts. Rescue experiments under adenovirus-mediated myocardial METTL3 overexpression confirmed that METTL3-mediated m6A methylation is essential in M-driven inhibition of myocardial hypertrophy. Collectively, MA exerts a significant anti-hypertrophy effect by regulating the modification of METTL3-mediated m6A methylation in vitro and in vivo. These findings may provide a platform for establishing a new target and strategy for cardiac hypertrophy treatment.