Impulsivity is a multidimensional personality trait and a common symptom of various mental disorders. In this paper, we review multiple perspectives such as behavioral studies, neuroimaging studies, and genetic association studies about response inhibition, which is one aspect of impulsivity. In various studies, the stop-signal paradigm (SSP) has been used to investigate inhibitory mechanisms. In our study, first, the procedure and theory of SSP are introduced. Second, the neural mechanism during response inhibition is ascertained using functional neuroimaging machinery. In particular, the activation of the right ventro-lateral prefrontal cortex associated with the success in response inhibition is examined. A number of genetic association studies showed that specific gene phenotypes affect the accuracy of response inhibition. Thus, understanding the mechanism of response inhibition is linked to the fundamental resolution of impulsive control disorders or personality disorders.