17 cases of maglignant tumors and 3 cases of inflammatory ulcers in ENT were diagnosed by HpD, a He-Cd laser or a Hg-lamp and spectroscopic analysis from September 1985 to June 1986. Tumors, ulcers and normal tissues have a fluorescent peak at 640nm, but their intensities are obviously different, thus providing a basis for diagnosis of malignant tumors.