Trust is the willingness to accept vulnerability based upon positive expectations of another’s behavior. Researchers have proposed the Dyadic Model, Rational Choice Model, Motivated Attributions Model and Perceived Trustworthiness-Cooperation Spiral Model of Trust Development. Psychological research has shown that betrayal has long-term bad effects on trust development. Recent research on the neural and physiological mechanism of trust has shown that oxytocin is associated with human trustworthiness and trust behavior and that trust is associated with the activation of dorsal striatum, anterior insula and brain areas that have been linked with reward processing: nucleus accumbens, the caudate nucleus, ventromedial frontal/orbitofrontal cortex, and rostral anterior cingulate cortex. Although there are numerous researches on trust to date at present, more research work are needed to disentangle the mysteries of the psychological and neurophysiologic underpinnings of human trust and trusting behavior.