The urinary system of all mammals is involved in filtration of toxic substances, removal of excess materials, conservation of water and maintenance of electrolyte balance (osmoregulation) and hence provides an optimal state conducive for metabolism throughout the body tissues as well as within inter-cellular spaces, thus maintaining homeostasis. The book embodies detailed observations on the structure, anatomy, histology, physiology and some aspects of histo-chemical investigations of kidney of Indian bats- which includes a frugivores belongs to family Pteropodidae of Suborder Megachiroptera as well as some animalivorous (viz, insectivorous, carnivorous, piscivorous, omnivorous and sanguinivorous) species of Suborder Microchiroptera respectively. The species inhabit different ecological habitats, have different dietary habits and possess variable body mass