The autofluorescence of normal skin, gastric mucosa, liver, and transplanted cancers excited by xenon ion laser (=365nm) was tested in rats, mice and nude mice. The transplanted cancers included human gastric cancer, human hepatocellular cancer, and human lung cancer, as well as S-180 leiomyosarcoma. The autofluorescence of specimens was spectroeopically measured and recorded and the experimental results are given.