Objective To explore the microstructural changes in white matter(WM)fibers of patients with post-stroke depression(PSD)by using automated fiber quantification(AFQ)and the relationship between changes in fibers and the Hamilton depression scale(HAMD).Methods The HAMD and MRI data were collected from stroke patients with a single anterior circulation infarction at 1-month follow-up.AFQ was used to extract the main fibers and calculate the fractional anisotropy(FA)of each node in each fiber.The difference of node FA in each fiber between groups and correlations between altered node FA and HAMD were then evaluated.Results Data were collected from 8 patients with PSD and 18 patients without PSD(non-PSD).Compared with that in non-PSD,the node FA in the callosum,left inferior longitudinal fasciculus,and uncinate fasciculus were significantly decreased in patients with PSD(P<0.05).The altered node FA values in the corpus callosum forceps minor(r=-0.418,P=0.047)and left uncinate fasciculus(r=-0.467,P=0.029)were negatively related to HAMD in patients with PSD.Conclusions AFQ can precisely measure the segmental microstructural damage of nerve fiber bundles in patients with PSD,of which segmental microstructural damage of the corpus callosum forceps and hook tracts is associated with the severity of depression.