Eight new dammarane-type triterpenoids (<b>1</b>-<b>8</b>), together with a related known analogue (<b>9</b>), were isolated from the roots of <i>Rhus chinensis</i>, a traditional Chinese medicine for treating coronary artery heart disease, guided by LC-MS analysis. Their structures were elucidated based on extensive spectroscopic analysis and quantum chemical calculations. Notably, compounds <b>1</b>-<b>7</b> and <b>9</b> possess an unusual 17<i>α-</i>side chain, and <b>1</b>-<b>4</b>, <b>6</b>, and <b>9</b> contain an uncommon 3-methyl-5,6-dihydro-2<i>H</i>-pyran-2-one moiety in the side chain. Compounds <b>1</b>-<b>5</b> and <b>9</b> have a 3,19-hemiketal bridge in the A ring. In an in vivo bioassay, <b>1</b>, <b>2</b>, and <b>4</b>-<b>6</b> exhibited significant preventive effects on zebrafish heart failure at 0.5 <i>μ</i>g/mL, improving heart dilatation, venous congestion, cardiac output, blood flow velocity, and heart rate. Compound <b>5</b>, displaying the most promising heart failure preventive activities, showed even better effects on increasing cardiac output (72%) and blood flow velocity (83%) than six first-line heart failure therapeutic drugs. Moreover, <b>1</b>, <b>2</b>, and <b>6</b> prevented the formation of thrombosis in zebrafish at 0.5 <i>μ</i>g/mL. The present investigation suggests that the new dammarane triterpenoids might be partially responsible for the utility of <i>R. chinensis</i> in treating coronary artery heart disease.