Dihydropyridine derivatives of the following formula, analogs thereof and pharmaceutically acceptable salts thereof have an activity of selectively inhibiting the action of N-type calcium channel. They are used as remedies for various diseases relating to the N-type calcium channel such as encephalopathies caused by the ischemia in the acute phase after the onset of cerebral infarction, cerebral hemorrhage or the like, Alzheimer's disease, etc.