Compared with the cardiac hypertrophy group, the serum cTn-I level and the mRNA expressions of COL1A1 and COL3A1 were significantly decreased in both the low-dose and high-dose tanshinone IIA groups, and no significant difference was found between the low-dose and high-dose tanshinone IIA groups, suggesting that tanshinone IIA has a protective effect on cardiac hypertrophy. The gene discussed is TNNI3; the disease is cardiac hypertrophy.