The present book includes four chapters that express the following briefly:Chapter One: This chapter involves an introduction about Kefir and its unique characteristics.Chapter Two: This section provides information on the importance of fermentation process including basics and types of fermentation factors effecting fermentation fermentative microorganisms and effects of fermented products on health. Chapter Three: This section provides information on the chemical microbial nutritional therapeutic and antibacterial properties of Kefir in addition to vitamin protein and mineral structure. Chapter Four: This section summarizes the importance of kefir and its characteristics.