Objective:To determine the microvessel density (MVD) in laryngeal carcinoma and its clinical significance.Method:Thirty-eight tumor specimens were selected from laryngeal cancer patients from January,1994 to March,1996.Histological sections of the tumors were stained immunohistochemically for factor Ⅷ.Using light microscopy,we counted microvessels per 400×field in the most active areas of tumor angiogenesis.Result:①The tumor blood vessels,composed of only one layer of endothelium were mainly distrbuted heterogenously in the interstitial tissue of laryngeal carcinoma with irregular lumen,poorly developed structure.②The MVD in the cancer tissues were statistically higher than that in peritumoral tissues (P＜0.01).③The MVD in the cancer tissues in group of patients with metastasis to cervical lymphonodes were statistically higher than in group without metastasis (P＜0.01),the MVD in the cancer tissues in group of advanced cases (Ⅲ,Ⅳ stages) were statistically higher than that in group of early cases (Ⅰ,Ⅱ stages,P＜0.01).④There was no statistically difference in MVD in the cancer tissue between supraglottic and glottic laryngeal carcinoma patients (P＞0.05).⑤There was no statistically difference in MVD in the cancer tissue among the G1,G2 and G3 group (P＞0.05).Conclusion:The laryngeal cancer blood vessels have some characteristics that don′t appear in normal vessels.It is suggested that tumor angiogenesis can promote tumor growth and metastasis and MVD may be a new prognostic indicator of laryngeal carcinoma.