Fluorescence is the light emission by an atom or molecule due to electronic transition, which is stimulated by the absorption of electromagnetic energy from external radiation. This phenomenon was first formally reported in 1565, but the term "fluorescence" was first proposed by Sir George Gabriel Strokes who was a British physicist and mathematician, and was derived from fluorspar in a footnote of his famous paper entitled "On the Change of Refrangibility of Light" published in 1852 . After that, fluorescence has been applied as an investigative tool in many different areas, from materials technology to life science. In 1953, fluorescent dyes were first applied in Medicine, using berberine sulfate, acid fuchsin and acridine to identify cancer cells in vaginal smears by staining the nucleic acid. In the following more than half century, fluorescence was gradually approaching into more medicine studies, focusing on tumour indication, cardiac ischemia evaluation, bile duct visualization, perfusion, etc. Nowadays, fluorescence image-guided surgery has become the new arena for this technology. It allows surgeons to real-time visualize the target structure intraoperatively to increase the efficacy of surgical tissue resection and meanwhile avoid unnecessary radical treatment during open surgery, laparoscopy, thoracoscopy, or endoscopes. fluorescence (600-650 nm) when excited by ultraviolet light (400nm). And also, the fluorophores used at the early stage had the disadvantages such as poor water solubility, short Strokes shifts, poor photophysical stability, low extinction coefficient and fluorescence quantum yield, high toxicity etc. Therefore, a good fluorophore should overcome all these drawbacks to allow spatial and temporal resolution, and should be stable enough to have a good observation window. However, regarding of fluorophores used for fluorescence image-guided surgery, it would require even more specifically and more sternly to achieve the most accuracy therapy during the operation. In the last decade, studies on this area have been concentrated on near-infrared (NIR) fluorophores which emit photons in the region between 650-900 nm which called in vivo optical window. Compared with fluorescence in visible region, NIR fluorescence has the advantages that it enhances tissue penetration (up to centimetres) to reduce light scattering and avoid tissue auto-fluorescence in living systems to achieve a higher signal-to-noise ratio.