Oral lichen planus (OLP) is an atypically keratinized and ulcerative lesion, producing severe pain and discomforts in the involved patients. Nevertheless, the etiological factor or the pathogenetic mechanism has not been clearly elucidated. In the present study, the different gene expressions were screened in 21 cases of OLP by immunohistochemical (IHC) array method using 80 antibodies, and found that the pathway of E-cadherin/β-catenin was abnormally expressed compared to the other essential genetic pathways. Particularly, the expressions of eIF5A, DHS, and DOHH, which are the biomarkers of protein translation, were remarkably reduced, nevertheless the expression of β-catenin was strongly positive in the 7 cases among 21 cases of OLP. The other expressions of p53, BCL-2, MDM-2, PAKT, BAX, BAK, BAD, NFkB, HO-1, etc, were usually weak or sparse, while the expressions of PCNA, CDK4, and HSP-70 were markedly increased. Taken together, it is presumed that the overexpression of β-catenin indicates the derangement of E-cad/β-catenin/NFkB pathway, causing the transcription of cellular proliferating genes in downstream events, i.e., PCNA and CDK4, and that it may be eventually relevant to the malignant potential of OLP epithelial cells. It is also suggested that the activation of β-catenin/TCF/LEF1 pathway be closely relevant to the immunological reaction of OLP with the accumulation of T-cells underneath the mucosal epithelium.