Objective:To explore the effect and potential mechanisms of CC chemokine ligand 8(CCL8)in cutaneous squa-mous cell carcinoma(CSCC).Methods:Collecting human skin squamous cell carcinoma tissue and normal skin tissue,and detect the expression of CCL8 through tissue immunofluorescence staining.After overexpression or inhibition of CCL8 in human skin squamous cell carcinoma cell line A431 using construction of myc-CCL8 overexpression plasmid or CCL8 siRNAs,cell viability,migration and invasion ability were detected.The expression levels of cell Epithelial-Mesenchymal Transition(EMT)related proteins(E-cadherin,ZO-1,SNAIL,N-cadherin)and JAK1/STAT3 pathway was detected by Western blot experiment.Re-sults:Compared with barely expressed in normal skin tissue,CCL8 was increased expressed in CSCC tissue(P<0.05).CCL8 could significantly promote the proliferation,migration,and invasion ability of A431 cells(P<0.05).CCL8 could remarkably activate the JAK1/STAT3 pathway in A431 cells,upregulate the expression of SNAIL and N-cadherin proteins,and downregu-late the expression of E-cadherin and ZO-1 proteins(P<0.05).Conclusion:CCL8 is up-regulated expressed in CSCC cells and can promote the EMT process of CSCC cells through the JAK1/STAT3 pathway,thereby facilitating CSCC cell proliferation,migration,and invasion,which provides ideas for clinical treatment of CSCC.