This model represents a humanized FCGR1 mouse, generated by substituting the mouse Fcgr1 gene sequence (inclusive of the UTR) with the corresponding human FCGR1 gene sequence. This modification enables the expression of human FcγRI in mice. Homozygous B6-hFCGR1 mice exclusively express human FcγRI receptors, with the proportion of cells expressing human FcγRI mirroring that of cells expressing mouse FcγRI in wild-type mice. Consequently, this model serves as a valuable tool for various research areas, including the evaluation of human IgG antibody affinity, exploration of the ADCC mechanism, investigation into immune cell phagocytosis and antigen presentation. Furthermore, it provides a platform for the preclinical assessment of therapeutic human IgG antibodies.