Objective:To explore the interaction effects on brain activity between the smoking addiction and weight status by resting-state functional magnetic resonance imaging.Methods:Retrospective analysis of clinical data and resting-state functional magnetic resonance imaging data were analyzed from 99 recruited subjects from January 2019 to December 2021. All participants were divided into four groups: overweight smokers ( n=24), normal-weight smokers ( n=28), overweight non-smokers ( n=19), and normal weight non-smokers ( n=28). Calculate regional homogeneity (ReHo) to reflect the internal brain activity of the subjects. Two-way ANOVA was used to detect the interaction effects between smoking addiction and overweight on ReHo by SPM12 software, correcting for age, years of education and head motion. Results:The interaction effect between smoking addiction and overweight on ReHo was significant in right superior frontal gyrus(x, y, z=15, 9, 60)(GRF corrected, Pvoxel<0.005, Pcluster<0.05). The ReHo value in the right superior frontal gyrus of overweight smokers was significantly higher than that of normal weight smokers ( t=3.768, P<0.001, Bonferroni corrected). The ReHo values in the right superior frontal gyrus of overweight non-smokers were significantly lower than those of normal weight non-smokers ( t=-3.242, P=0.002, Bonferroni corrected). The ReHo values in the right superior frontal gyurs of normal-weight smokers were significantly lower than those of normal weight non-smokers( t=-3.540, P=0.001, Bonferroni corrected). The ReHo values in the right superior frontal gyrus of overweight smokers were significantly higher than those of overweight non-smokers ( t=3.392, P=0.002, Bonferroni corrected). Correlation analyses showed that the strengthen ReHo value in right superior frontal gyrus was positively associated with pack-year in smoking addicts( r=0.387, P=0.007, Bonferroni corrected). Conclusion:Smoking addiction and overweight have an antagonistic effect on brain activity in the right superior frontal gyrus, which may provide potential therapeutic targets for individuals with comorbidity of smoking addiction and overweight.