Activation and role of epidermal growth factor (EGF)- epidermal growth factor receptor (EGFR)- mitogen-activated protein kinase (MAPK) signaling pathway in cell proliferation. Methods calf serum (FCS), EGF(0. 1, 1,1,150, 100 ng/ml) and the above concentrations were determined respectively. The expression of EGFRmRNA and protein in RPE cells was detected by in situ hybridization and immunocytochemistry. Immunohistochemical staining was performed with anti-phosphorylated extracellular signal-regulated kinase (ERK) 1/2 antibody to observe the activation of MAPK. Results The optimal concentration of EGF in 10% FCS modified Eagle medium (DMEM) was 1 ng/ml, and in 0. 1% FCS DMEM, the optimal concentration was 10 ng/ml. After EGF treatment, the expression of phosphorylated ERK 1/2 antibody was transferred from cytoplasm to nucleus. Conclusion EGF promotes the expression of EGFRmRNA and protein in RPE cells in a concentration-dependent manner, and has a concentration-dependent nuclear translocation effect on MAPK. It is speculated that EGF-EGFR-MAPK signaling pathway may play an important role in the proliferation of RPE cells, and serum can obviously promote this process.