Abstract: Objective:To investigate the expression of PKCζ protein in adenocarcinoma of the lung and its relationship with invasion, metastasis and prognosis, and to initially analyze the molecular mechanism of metastasis. Methods: Activation of PKC ζ was inhibi ted in A549 cel ls. The effect was evaluated using chemotaxis and adhesion assays. The expression of PKC ζ in adenocarcinoma of the lung was detected using immunohistochemistry in 48randomly chosen tissues (using integrated clinical and fol low-up data). The relationship between PKC ζ and cl inicopathologic parameters was then analyzed. Results:Atypical Protein Kinase C participated in the process of chemotaxis and adhesion of lung cancer cel ls. Inhibi tion of PKC ζ activation markedly decreased EGF-induced chemotaxis and adhesion of A549 cells. Of the 48adenocarcinoma tissues examined, 52% showed positive expression of PKC ζ. PKC ζ was detected in the cytoplasm. The expression of PKC ζ protein was associated with lymph node metastasis (P<0.05), but was not correlated with other clinicopathologic parameters, such as age, gender, tumor size, and so on. Survival analysis (Log-rank test) showed that PKCζ expression was also correlated with prognostic factors (P<0.05). Conclusion:Overexpression of PKC ζ protein is associated with invasion and metastasis of adenocarcinoma of the lung, and may be used as a biomarker for the prognosis of adenocarcinoma of the lung.