In recent five years,brain imaging studies suggested that internet addicts' neural pathway have abnormalities in reward circuits,executive control system,and decision-making system when they are in resting state or induced state.For internet addicts,in the aspect of reward circuits,they showed decreased metabolism level when undergoing a resting-state fMRI scan,and enhanced reward sensitivity as well as decreased loss sensitivity when functioning.In the aspect of executive control system,the related brain areas were associated with reduced white matter integrity and disrupted functional comnectivity in resting-state.When the task was internet-related,internet addicts showed enhanced executive control function.However,when the task was not internet-related,they showed reduced executive control function.In the aspect of decision-making system,reduced cortical thickness in related brain areas was found when internet addicts are in resting-state,and they possess high impulsivity and high risk tendency when they are in induced state.These findings are consistent with the conclusions of substance addicts which are based on the research of brain imaging,therefore,we preliminary think the internet addiction is a new type of addictive mental disorder.