Human beings are remarkably sensitive to recognizing the motion of biological entities in complex visual scenes, even when it is depicted with a handful of point-lights attached to the head and major joints. A number of studies demonstrated that biological motion contains not only form and motion information, but also include many sorts of socially relevant information about an agent such as identity, gender, emotions, intentions and so on. One could recognize the biological motion as himself or his friends without face and other familiar cues, the visual experience of observing others’ action and the movement experience executed by participant himself or herself could influence the identity perception. Observers are more familiar with their own biological motion. Motion information alone could make one to distinguish anger, happiness, surprise or other mental states automatically, social context would improve the ability of emotion perception of biological motion and different display conditions will also influence the processing progress, for example the inversion display will decrease the emotion perception. People react differently to social and non-social motion. Eye movements researches revealed a spontaneous, fast and durable bias of overt visual-spatial attention favor for the perception of social motion and a different visual scanpath for social bigological motion compared to non-social stimulus. These findings constitute a basis for the investigation of a ‘social intention’ bias in perception of human biological motion. The other interesting thing is observer could estimate whether the biological motion walkers are walking backward or forward to the observer, but the perception was affected by facing bias. The observer could also change his or her behavior in social interaction according to the social information, while concrete content of each dimension and their relationship between each other are still under exploring. On the other hand, action cognition is very important to social cognition for human being and animals. There has been many researches have confirmed that there is an inner connection between visual biological motion processing and deficits in social cognition. Individuals with autistic spectrum disorders always have social cognition impairments, but there are contradictory conclusion between young children, adolescents and adults with autism on their performance of biological motion pilot task. Brain imaging data revealed a decreasing brain activity in the superior temporal sulcus which is very important in the processing of biological motion. The perception of biological motion also affected in the people with schizophrenia. Williams syndrome individuals exhibit intact or even enhanced social skills, and they are reported to be unimpaired on biological motion tasks. Down syndrome and other genetic conditions with distinct profiles of social cognitive impairments, whether biological motion processing is intact in these disorders are essential to proclaim the hypothesis that intact biological motion processing may be considered a fundamental basis for preserved social cognition. Future research should shed light on functional brain mechanisms associated with impairments in social information derived from biological motion, in order to provide more evidence whether biological motion could be a hallmark of social cognition and whether it could be applied in the diagnosis and treatment.