Qingda granule (QDG), simplified from Qingxuan Jiangya Decoction, is a well-known traditional Chinese medicine formula that has been used for decades to treat hypertension. However, the cardioprotective effects of QDG on Ang II-induced hypertension remain unknown. This study aimed to investigate the effects of QDG on hypertension-induced cardiac hypertrophy and apoptosis, as well as explore its underlying mechanisms. Mice were infused with Ang II (500 ng/kg/min) or saline solution as control, then administered oral QDG (1.145 g/kg/day) or saline for two weeks. QDG treatment attenuated the elevation in blood pressure caused by Ang II, as well as the decreased left ventricle ejection fractions and fractional shortening. Moreover, QDG treatment significantly alleviated the Ang II-induced elevation of the ratio of heart weight to tibia length, as well as cardiac injury, hypertrophy, and apoptosis. In cultured H9C2 cells stimulated with Ang II, QDG partially reversed the increase in cell surface area and number of apoptotic cells, up-regulation of hypertrophy markers ANP and BNP, and activation of caspases-9 and -3. QDG also partially reversed Ang II-induced accumulation of reactive oxygen species (ROS), depolarization of the mitochondrial membrane, release of cytochrome C, up-regulation of Bax, and decrease in levels of p-PI3K, p-AKT, and Bcl-2. These results suggest that QDG can significantly attenuate Ang II-induced hypertension, cardiac hypertrophy and apoptosis, and it may exert these effects in part by suppressing ROS production and activating the PI3K/AKT signaling pathway.