Patch-clamp fluorometry is a powerful biophysical method that allows the researcher to monitor conformational changes of ion channel in real time, and to correlate dynamic structural information to functional states. As a natural combination of the classic patch-clamping method and state-of-art optical methods, patch-clamp fluorometry is applicable to a wide spectrum of channel studies with unprecedent spatial-temporal resolutions. Unlike other structure-oriented methods such as X-ray crystallography and cryo-EM, patch-clamp fluorometry provides dynamic structural information of channel proteins in intact cell membrane under physiological conditions.