The primary aim of this thesis is to research Gelsolin Family Proteins. Gelsolin is undoubtedly an actin-binding protein which is an important regulator of actin filament assembly and disassembly. The actin cytoskeleton serves as a advanced structure that carries out a multitude of cellular functions. Gelsolin is probably the most powerful members of the actin-severing gelsolin/villin superfamily. Some topics discussed in this project are: Actin dynamics, Actin-binding proteins, Actin dynamics at the cell membrane, Cytoskeleton and pathology, etc.