Background: Formation of a functional precursor B cell receptor (pre-BCR) is dependent on N-glycosylation of -heavy chains (HC). Results: Lack of core fucosylation of HC attenuated the interaction between HC and 5. Conclusion: Core fucosylation of HC mediates the assembly of pre-BCR. Significance: Learning how Fut8 regulates the assembly of pre-BCR is crucial for understanding pre-B cell development.