Objective To investigate the expression of protein kinase CK2α in thyroid carcinoma SW579 cells and its significance.Methods SW579 cells and Hacat cells were cultured in vitro and the expression levels of protein kinase CK2α mRNA and protein in SW579 cells and Hacat cells were measured by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting.Moreover,CK2 activity was also measured.Results It was showed that the mRNA (0.92 ±0.01 vs 0.52 ±0.02,t =19.24,P ＜0.01)and protein(0.98 ±0.01 vs 0.37 ±0.02,t =24.14,P ＜0.01) expression of protein kinase CK2αwere significantly stronger in SW579 cells relative to Hacat cells.Conclusions Formation and development of thyroid carcinoma may be in connection with the overexpression of protein kinase CK2α.