Objective: To analyze resting state electroencephalography (EEG) theta/beta power ratio (TBR) and motor development characteristics in children aged 4-8 years with attention deficit hyperactivity disorder (ADHD) and typically developing children, so as to examine the association between TBR in brain regions showing ADHD related differences and motor coordination ability. Methods: From July to September 2025, a total of 80 children aged 4-8 years were enrolled (40 in the ADHD group were recruited at Beijing Children s Hospital and 40 in the typically developing control group were recruited at a kindergarten and a primary school in Weifang). Three minute eyes open resting state EEG was collected to calculate TBR in the frontal, central, parietal, temporal, and occipital regions. The Movement Assessment Battery for Children-2 (MABC-2) and the Test of Gross Motor Development-3 (TGMD-3) were used to assess motor development. Between group comparisons were performed using t-test and analysis of covariance. Pearson correlation and partial correlation analyses were used to explore the relationships between regional TBR and motor development indicators; multiple linear regression analysis was used to examine the predictive effect of regional TBR on motor development. Results: After adjustment, TBR in the frontal, central, parietal, and temporal regions was higher in the ADHD group than in the control group (all P <0.05). After adjustment, TGMD-3 object control skill scores (32.50±1.22 ，38.65±1.06) and total scores (71.05±1.98, 80.25±1.72), as well as MABC-2 fine motor (7.02±0.22, 8.96± 0.19), coordination (7.52±0.23, 8.40±0.20), balance (7.25±0.24, 8.98±0.21), and total scores (21.79±0.51, 26.34± 0.44 ), were lower in the ADHD group than in the control group ( F =6.85, 6.48, 22.50, 5.16, 13.75, 28.60, all P <0.05). Pearson correlation analysis showed that within the ADHD group, central and parietal TBR were negatively correlated with MABC-2 total score ( r = -0.32 , -0.34, both P <0.05). Multiple linear regression analysis showed that after controlling for sex, age, height, weight, and body mass index in children with ADHD, parietal TBR remained negatively associated with MABC-2 total score ( β =-0.21, P <0.05). Conclusion ADHD related cortical arousal characteristics in children aged 4-8 years may be associated with their motor deficits.