Semen consists of two major components, sperm & seminal plasma. Seminal plasma is secreted by testis & accessory sex glands and is a highly complex fluid contains various compounds including seminal plasma proteins. There are different seminal plasma proteins in bovine species; one such protein is BSP proteins. It is major protein fraction (50-70%) of bovine seminal plasma and belongs to the family of phospholipid-binding proteins. These proteins are either beneficial or harmful on storage of the sperm. Therefore, BSP proteins act like a double-edged sword. They bind to sperm membrane choline phospholipids at ejaculation and also bind to capacitation factors and promote sperm capacitation. On the other hand, BSP proteins also induce cholesterol and phospholipids efflux. Thus, continuous exposure of sperm to BSP is detrimental to sperm in liquid or frozen semen. Therefore its concentration plays important role in semen preservation. This book explains about the origin and function of bovine seminal plasma proteins in bubaline species. This book is useful for scientists working in semen cryopreservation studies and semen biology, frozen semen banks and cattle and buffalo breeders.