The current trends in biomedical research gloabally rely upon experimental animals for their pivotal contribution in proper designs of experiments to understand the underlying mechanisms of various diseases.. These animals which are mostly rodents; are broadly preferred in biomedical research for certain characters like well established gene maps, easy adaptibility and ability to produce large number of offsprings at breeding. Besides, these animals are well known for high compliance to different diets beacuse of their characteristic digestive system structure, and high susceptibility to targeted non-infectious or genetic diseases which may cause harm to humans. Rodents are fed with different diets that meet their maintenance and productivity requirements specific to each specie and strain, highly depending upon the production or experimental purposes. Commercial diets in pellet or extruded form consisting of various feed raw materials of plant and / or animal origin, are the most widely used diets for feeding and special diets are also prepared according to the requirements of research. This review deals in comprehending the details about orgin, history, feeding behaviours and strains of variously used experimental animals. Besides, nutrient requirements of this animals; characteristics, type, content, physical form of diet and effects of environmental factors on their diet have been discussed.