In this study, we used DKI to quantify the microscopic changes of residual liver in two groups of rats with different proportions of a partial hepatectomy (PH). All the rats underwent DWI to acquire DKI data at baseline and multiple time points after surgery. The results showed that DKI-derived MD in the 70% PH group were lower than in the 30% PH group at all time points after surgery. MD decreased to a minimum by the fifth day before rising back to baseline. This suggests that DKI is a practical technique for the timely evaluation of the liver regeneration process.