Objective:Analyze the relationship between the change of mucosal wave and the infiltrating level of early laryngeal carcinoma so as to guide the cordectomy. Method:Retrospective research on patients of 1a stage without anterior commissure invasion who received simple CO2 laser therapy because of primary glottic laryngeal squamous cell carcinoma. Result:Records of 320 patients including 22 patients who have slightly reduced according to the mucosal wave prompts before operation, 49 patients mucosal wave moderately reduced, 151 patients mucosal wave severely reduced, and 98 patients have mucosal wave disappeared according to stroboscopic assessment. Post-pathological evidence shows that 16 patients had their tumor infiltration into the epithelial layer, of which, 15 received the Ⅲ type laser surgery, 1 patient received the Ⅳ type laser surgery; 189 patients had their tumor infiltration into the lamina propria, of which, 148 received the Ⅲ type laser surgery, 41 received the Ⅳ type laser surgery; and 115 patients had their tumor infiltration into the vocal cord muscle layer, of which, 77 received the Ⅲ type laser surgery, 38 received the Ⅳ type laser surgery. Analyzed according to the Kaplan-Meier method, it shows that their five-year overall survival rate was 94.0%, the five-year disease-specific survival rate was 98.4%; and five-year local-region control rate was 91.2%. Change of the mucosal wave and the tumor infiltrating level have significant correlation; patients whose tumor infiltration had reached the lamina propria received the Ⅲ and Ⅳ type laser surgical treatment, their five-year overall survival rate and their five-year local-region area control rate have no obvious difference; patients whose tumor infiltration have reached the muscular layer received the Ⅲ and Ⅳ type laser surgical treatment, their five-year overall survival rate and their five-year local-region area control rate have no significant difference. Conclusion:This research shows that, change of the mucosal wave can, to a certain extent, prompt the tumor infiltration degree and guide in operation; for patients who are suspected of laryngeal carcinoma, when mucosal wave before operation prompts moderate-sever reduction or disappearance, to ensure bottom incisal margin clean, it should be cut at least to the muscular layer; for laryngeal cancer patients whose infiltrating mucosal wave disappears, it prompts that the tumor may have infiltrated to the muscular layer, and the Ⅲ and Ⅳ type laser surgery will have no significant prognostic influence.