Objective To investigate the changes in amplitude of low-frequency fluctuations（ ALFF） and fractional amplitude of low-frequency fluctuations（ fALFF） in resting-state functional magnetic resonance imaging（ rs-fMRI） among depressive disorder adolescents with attempted suicide， and to explore their clinical significance. Methods This study was a cross-sectional study. A total of 65 depressive disorder adolescents admitted to Suzhou Guangji Hospital from October 2022 to July 2023 were selected as research subjects. According to whether there was a history of attempted suicide within the past year， patients were divided into an adolescent depressive disorder group with attempted suicide（ SD group，n=32） and an adolescent depressive disorder group without attempted suicide（ ND group，n=33）. At the same time， 31 healthy individuals were recruited from the community as a healthy control group（ HC group）. All participants underwent rs-fMRI， and ALFF and fALFF values were calculated based on the imaging data. The severity of depressive disorder was assessed using the Patient Health Questionnaire-9（ PHQ-9）， and suicide risk was evaluated using the suicide subscale of the Mini-International Neuropsychiatric Interview for Children and Adolescents（ MINIKid）. Analysis of variance was used to compare differences among the three groups and to conduct post-hoc tests. On this basis， Spearman correlation was used to analyze the correlation between ALFF and fALFF values in different brain regions and PHQ-9 scores and MINI-Kid suicide subscale scores. Results Compared with the HC group， patients in the SD group exhibited statistically significant increases in ALFF values in the right superior frontal gyrus and in fALFF values in the left superior frontal gyrus， bilateral middle frontal gyrus， and left supramarginal gyrus， while fALFF values in the left precentral gyrus were statistically reduced（ all voxellevel P＜ 0.001， cluster-level P＜ 0.05， GRF-corrected）. In the ND group， there were statistically significant increases in ALFF values in the left angular gyrus and in fALFF values in the right middle frontal gyrus， left supramarginal gyrus， left medial gyrus， and parahippocampal gyrus， as well as a statistically significant decrease in fALFF values in the bilateral supratemporal gyrus（ all voxel-level P＜0.001， cluster-level P＜0.05， GRF-corrected）. Compared with the ND group， the patients in the SD group showed elevated fALFF values in the left supratemporal gyrus and reduced fALFF values in the left insula and right postcentral gyrus， with all differences being statistically significant（ all voxel-level P＜ 0.001， cluster-level P＜ 0.05， GRF-corrected）. Correlation analysis revealed that the fALFF values in the left supramarginal gyrus of patients in the SD group were negatively correlated with the PHQ-9 scores， and this difference was statistically significant（ r=-0.469， P=0.007）. Conclusions Depressive disorder adolescents with attempted suicide exhibit abnormal brain activity in multiple regions， and the fALFF values in the left superior marginal gyrus are negatively correlated with the severity of adolescent depressive disorder.