Optical imaging to visualize biomolecules holds promise for early and precise detection of various diseases. Rapid development of technologies for laser oscillators, spectroscopes, and detectors has made it possible to study biochemical changes associated with diseases which were difficult to visualize in situ without labeling. In this paper, we introduced our recent non-labeling imaging studies by using Raman scattering light and autofluorescence. Our results suggest the potential of Raman scattering light and autofluorescence measurements for the non-labeling detection of various diseased tissues based on their molecular compositions.