AbstractBackgroundMicrovascular invasion (MVI) was a critical high‐risk factor for postoperative recurrence and adverse prognosis in patients with hepatocellular carcinoma (HCC), and there were no reliable non‐invasive pre‐operative diagnostic markers. The exosomal N‐glycan profile was closely related to the invasion and immune escape of HCC. Therefore, this article investigated the expression of N‐glycan profiles in serum exosomes of patients with HCC and its clinical significance for MVI.MethodsSerum samples from 210 patients with HCC were collected and randomly divided into modeling and validation cohorts. The abundances of N‐glycans in serum exosomes with different MVI grades were determined. A diagnostic model for MVI in HCC based on N‐glycosylation was constructed and the diagnostic value was analyzed.ResultsIn the modeling cohort, comparing groups M0 with M2, the area under the receiver operating characteristic (AUC) of the diagnostic model namely SUM (AUCSUM) was 0.861, the sensitivity of SUM was 92.68%, and the specificity of SUM was 79.41%, all of which were higher than the seven individual indexes (containing Peak 1, Peak 6, Peak 9, Peak 10, Peak 12, AFP, and PIVKA‐II). In the comparison between the M1 and M2 groups, the AUCSUM was 0.749, the sensitivity of SUM was 79.07%, and the specificity of SUM was 76.60%, all of which were higher than the seven individual indexes. When comparing the M0 and M1 groups, the AUCSUM was 0.712, the sensitivity of SUM was 88.57%, and the specificity of SUM was 65.00%. The AUCSUM and sensitivity of SUM were higher than the seven individual indexes and the specificity of SUM was slightly lower than that of AFP (68.18%) but higher than other individual indexes. The results of the validation cohort were similar to those of the modeling cohort.ConclusionThe SUM model of serum exosomes can serve as an auxiliary diagnostic index for MVI staging in patients with HCC.