A stem cell niche is defined as the microenvironment surrounding stem cells, and it is generally composed of adjacent cells, adhensive molecules, extracellular matrix, and so on. Stem cells in different tissues differ in their niches. Stem cell niches regulate stem cell self-renewal and differentiation. According to the recent studies in stem cell niches, this review summarizes on the constitution and function of germ-line stem cells niche in fruit, hematopoietic stem cell niche, intestinal stem cell niche, hair follicle epidermal stem cell niche and neural stem cell niche in mammals, and discusses the internal mechanism of niches'action on stem cells.