Abstract: Objective To investigate the characteristic patterns of gray matter volume and neurotransmitter deficits in subjective cognitive decline (SCD) patients with metacognitive impairment, and their correlation with cognitive performance. Methods A total of 100 SCD patients and 100 healthy controls (HCs) were included into the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. Based on the presence of metacognitive impairment, these SCD patients were divided into two groups (n=50): a normal metacognition group and an impaired metacognition group. The voxel-based gray matter volume and neurotransmitter changes in each group were analyzed by voxel-based morphometry (VBM) and JuSpace toolbox. Results Compared with the HCs group, the impaired metacognition group showed gray matter atrophy in the frontal, temporal, and parietal lobes, while the normal metacognition group presented gray matter atrophy in the postcentral gyrus. Compared with the normal metacognition group, the impaired metacognition group exhibited gray matter atrophy in the middle temporal gyrus and increased gray matter in the postcentral gyrus. The atrophy of the middle temporal gyrus in SCD patients with metacognitive impairment was spatially closely related to the distribution of 5HT1b, D1, NMDA, and mGluR5. Conclusions SCD patients with metacognitive impairment have specific middle temporal gyrus atrophy related to neurotransmitter deficits, which is closely associated with cognitive function.