The present invention relates to a heart targeting agent comprising tannic acid, in which the agent aids a heart disease therapeutic drug to be delivered to the heart and bind to the cardiac myocardium by inducing tannylation of the drug so as to make heart targeting and accumulation of the drug possible. Unlike the conventional invasive method used for the traditional drugs to be able to target the heart, the agent of the present invention can help a drug to target the heart with high efficiency just via non-invasive intravenous administration.