ObjectiveTo evaluate the feasibility of susceptibility weighted imaging (SWI) in determining pathologic grade of hepatocellular carcinoma (HCC) in rat model. MethodsRat models were established first and SWI was performed before killing rats to be examined pathologically. The Edmondson-Steiner grading was used as gold reference for histological grade of HCC. The characters of intratumoral susceptibility signal intensity (ITSS) between lowand high-grade HCCs were compared. The diagnostic value of ITSS in differentiating lowfrom high-grade HCCs was evaluated. ResultsForty eight rat models of HCC were successfully established. Thirty two HCCs (18 low-grade HCCs and 14 highgrade HCCs) were included finally. The incidence of ITSS between two groups was not significant (P=0.113). Characters including component of ITSS (P=0.002) and ratio of ITSS in HCC (P < 0.001) were compared between lowand high-grade HCCs, which were both statistically significant. When score of ratio of ITSS in HCC was assessed as 2 scores, the sensitivity and specificity of ITSS in differentiating lowfrom high-grade HCCs were 85.7% (95% CI:74.9%-96.5%) and 94.4% (95% CI:83.6%-100%) respectively, and the area under roc curve (AUC) was 0.917. ConclusionSWI can evaluate characters of ITSS in HCC and can be an alternative method in grading HCC.