Environmental enrichment is the process of providing stimulating environments for zoo animals in order for them to demonstrate their species-typical behavior, to allow them exercise control or choice over their environment, and to enhance their well-being. We are aimed to provide the available knowledges about the animal enrichment programs for zoo animals through literature review. As the results, we reviewed the design of stimulating and naturalistic enclosures, the housing etc. Enrichment includes the design of stimulating and naturalistic enclosures, the housing of appropriate social groups in zoo, and the introduction of objects, sounds, smells or other stimuli in the animal’s environment. Conclusionally, environmental enrichment is just as critical to Zoo animal welfare as nutrition and veterinary medicine. At the zoos, enrichment will be an integral part of the daily care of the species in the collection.