Current application of fluorescence spectroscopy on characterizing proteins is more and more relevant, because it is employed to study their behavior at the molcular level, which may be influenced by many factors such as protein conformation, presence of co-factors or ligands, environment conditions. Fluorescence spectroscopy can provide insights into protein folding/unfolding, quality, stability and interactions, which are crucial for various food applications. Intrinsic fluorescence of proteins is mainly predominated by tryptophan probe, while 8-anilino-1-naphthalenesulfonic acid (ANS) is the main extrinsic fluorescence used to determine the surface hydrophobicity of proteins, which is an indicator of the protein conformation change. The present chapter will be dedicated to the use of fluorescence spectroscopy to study the plant-based proteins and their relation to techno-functional properties, giving an insight of the current status about the main plant-based proteins.