Hippocampus is a part of limbic system involving both neurodegenerative disease and emotional regulation circuit. This study aimed to use MRI automated subfield hippocampal volumetric analysis to differentiate mild cognitive impairment (MCI) from major depressive disorder (MDD) and age-matched healthy elderly (HE) subjects. We found a trend of relative smaller size in several subfield hippocampal regions in MCI than MDD patients. Even though, there were no statistical significance. These may raise possibility of MRI volumetry to be the tool for discriminating early neurodegenerative disease from major depressive disorder.