Objective To explore the neurochemical changes of the hippocampus in the patients with postnatal depression. Methods A total of 20 postnatal depression patients and 20 postnatal healthy controls were recruited， and the hippocampal head， body and tail were evaluated by magnetic resonance spectroscopy （1H-MRS）. The indicators included N-acetylaspartic acid（ NAA）， choline complex（ Cho）， creatine（ Cr）， inositol （MI）， and calculated the ratio. Results The values of NAA/Cr in the bilateral hippocampal head， body of the postnatal?depression patients were significantly higher than the health controls（ P ＜ 0.05）， while there was no significant difference in the hippocampal tail between the two groups（ P＞0.05）. There were no significant differences in the value of Cho /Cr in the hippocampal head， body or tail between the two groups（ P＞0.05）. The value of MI/Cr in the bilateral hippocampal head of the postnatal depression patients was significantly decreased than the health controls（ P＜ 0.05）， while there was no significant difference in the hippocampal tail between the two groups（ P＞ 0.05）. Conclusions Metabolism of hippocampus in patients with postpartum depression changes， which may constitute the neurobiological basis of postpartum depression.