The stromal microvasculature in 27 cases of nasopharyngeal precancerous lesions (NPP) were studied for morphological features and parameter quantitation by computerized image analysis system. FVIIIR:Ag was used as a vascular endothelium marker to show the blood vessels by immunohistochemistry. The microscopic and quantitative results show that most cases (79%) had hyperplastic abnormal blood vessels similar to the stromal neovascularization of nasopharyngeal carcinoma (NPC). These findings suggest that angiogenesis may be a prerequisite to cancerous transformation of nasopharyngeal epithelium, and that cases of NPP with neovascularization have a high tendency to cancerous transformation.