Abstract: The principle and important applications of lasers and optoelectronics in health care treatment and biology are reviewed, including optical biopsy, nonablative optical treatment and biophotonic technology. The history, main advantages as well as recent progress and development of optical biopsy in pathological discrimination are first introduced. In particular, laser-induced fluorescence spectroscopy and imaging techniques are described in detail. Secondly, the nonablative mechanism and clinical applications of optical treatment are summarized. Thirdly, the principle and applications of confocal laser scanning microscopic imaging, multi-photon excited fluorescence microscopic imaging, near-field optical microscopic imaging, and optical tweezers are described. Finally, future applications and prospects are briefly discussed.