The pathogenesis of cardiovascular diseases of individuals is largely resulted from their maternal obesity (MO), which attracts much attention in recent years. In addition to jeopardizing maternal health, MO increases the risks of offspring heart attack via affecting development of cardiovascular system. The prenatal high-calorie intake leads to the fetal overnutrition that alters the use of fatty acids, glucose, and ketones in cardiomyocytes. Studies indicated that the influences of MO on offspring include the cardiomyocyte metabolism and remodeling, as well as heart ROS increase, which therefore stimulates mTOR and Hippo pathways to induce cardiomyocyte proliferation and hypertrophy. Interestingly, Hippo pathway could potentially be a therapeutic target of cardiomyocyte hypertrophy. This review aims to disclose the role of MO in regulating the fetal cardiomyocyte metabolism, the offspring cardiomyocyte hypertrophy and the epigenetic mechanism thereof. Furthermore, the long-term effects of MO on offspring cardiomyocyte health is discussed. It is suggested that the metabolic memory, the cross-generational genetic effects, and the early-life intervention be laid great emphasis for the future researches.