Mismatch negativity (MMN), evoked by suddenly appeared discriminable change (deviant stimulus) in a sequence of repetitive stimuli (standard stimulus), is a negative component of event-related potential (ERP) with short duration. MMN could be found in both humans and animals and could be evoked in multiple perceptual modalities such as vision, auditory sense and olfactory sense without attention, suggesting that it reflects the brain′s automatic perception of the change in perceptual environment which is very important for animals′ survival and reproductive success. In order to clarify both advantages and disadvantages of MMN for future studies on animal cognition, this paper reviews MMN studies on various animal taxa, its generation mechanisms and generators as well as the influence factors. Finally, the possible prospect of MMN study in the future is proposed.