Objective: To study the malignant transformation tendency of oral lichen planus (OLP). Methods: The expression of epidermal growth factor receptor was determined with an immunhistochemical method in cases with oral lichen planus, oral leukoplakia, oral squamous cell carcinoma, and normal oral mucosa. Results: The positive rates of normal mucosa, oral lichen planus, oral leukoplakia, and carcinoma were 0%, 37.5%, 50%, and 57.14%, respectively. Conclusion: The results indicate that oral lichen planus may have a tendency for malignant transformation and may be regarded as a precancerous lesion of the oral mucosa.