In two experiments, we aim to examine the cue-elicited craving and possible brain structural abnormalities in the betel nut chewers. Previous studies have shown that arecoline can have widespread effect in cortical and subcortical areas. However, it is still unclear whether habitual betel nut chewing affects brain areas involving addiction (e.g., the amygdala-striatal system and prefrontal control system). This question is important because the balance of these two systems is considered to be critical to substance use. In Experiment 1, we will adopt the cue-reactivity paradigm and task-based functional MRI (fMRI) to evaluate craving induced by the betel nut cues. In Experiment 2, we will adopt the diffusion MRI (dMRI) and resting-state fMRI to evaluate betel nut chewers’ brain structure involving addiction. In addition to brain imaging, we use stop-signal task and single-category implicit attitude task (SC-IAT) to assess betel nut chewers’ inhibitory control and implicit attitude toward betel nut, respectively. The behavioral performances of stop-signal task and SC-IAT are expected to correlate to the brain structures revealed by dMRI and resting-state fMRI. In the stop signal task, participants perform a shape recognition task, but in some trials, an auditory warning (a stop signal) instructs them to withhold their response. Individuals with better inhibitory control are likely to inhibit a prepotent response on stop trials. The stop-signal reaction time (SSRT) was primarily analyzed to assess the inhibitory control ability. It reflects the time required to process stop signals and to withhold responses; therefore, longer SSRT indicates a worse inhibitory control. The deficits in SSRT have been pronounced in the dependent group. The SC-IAT has been developed to measure the implicit attitudes to an attitude object. Participants are instructed to categorize the stimulus (words and pictures) at the center of the display under the categories of ’pleasant’ and ’unpleasant’ as quickly and accurately as possible. Short time to categorize the attitude object (e.g., betel nut) to the ’pleasant’ label indicate an implicit attitude favoring this attitude object.