The present invention relates to 3,4-dihydroquinazoline derivatives as T-type calcium channel blockers and a method of preparing the same. The present invention further relates to a composition comprising the same. The composition comprising the 3,4-dihydroquinazoline derivatives of the present invention can be effectively used for preventing and treating angina pectoris, high blood pressure, myocardial disease, pain and epilepsy by blocking the T-type calcium channel.