Objective To observe the characteristics of local spontaneous brain activity in patients with mild traumatic brain injury(mTBI)in acute stage,and to explore the pathogenesis of the acute stage.Methods From July 2021 to June 2022,38 patients with acute mTBI who were admitted to the Department of Emergency and Department of Bone and Traumatology,the First Affiliated Hospital of Baotou Medical Col-lege,Inner Mongolia University of Science and Technology were selected as the mTBI group,and 39 healthy patients matching gender and age in the community were selected as the control group.Magnetic resonance da-ta and clinical assessment scale data were collected to compare the differences of low-frequency amplitude(ALFF)and local consistency(ReHo)of brain activity between the two groups,and to extract the ALFF and ReHo values of brain areas with significant differences between the two groups for correlation analysis.The ALFF and ReHo values of the significantly different brain areas were evaluated by receiver operating charac-teristic(ROC)curves to distinguish the diagnostic efficacy of the two groups.Results In the mTBI group,the ALFF value of the right caudate nucleus and the right supplementary motor area was significantly de-creased,the ReHo value of the left dorsolateral superior frontal gyrus was increased,and the ReHo value of the right orbital inferior frontal gyrus was decreased(P＜0.05).In the mTBI group,the ReHo value of left dorsolateral superior frontal gyrus was negatively correlated with self—rating anxiety scale(SAS)scores after trauma,and positively correlated with abstract and orientation scores(P＜0.05),while the ALFF value of the right supplementary motor area was positively correlated with named scores(P＜0.05).The ALFF value of the right caudate nucleus and the right supplementary motor area,the ReHo value of the left dorsolateral su-perior frontal gyrus and the right orbital inferior frontal gyrus were more effective in distinguishing them,and the area under the ROC curve were 0.749,0.760,0.794,0.798,respectively(P＜0.05).Conclusion The ab-normal changes of local spontaneous brain activity in the right caudate nucleus,the right supplementary motor area,the left dorsolateral superior frontal gyrus and the right orbital inferior frontal gyrus may be related to the neuropathological mechanism of cognitive impairment and anxiety symptoms in early mTBI patients.