Abstract: Objectives: To investigate the adverse events, the immune aging and the immunotherapeutic toxicity of elderly cancer patients over 75 years old received immune checkpoint inhibitors and the management of related toxicity. Methods: The adverse events information of solid cancer patients who received pd-1/pd-l1 immune checkpoint inhibitors treated in the First Affiliated Hospital of Nanjing Medical University from January 1, 2018 to December 31, 2021 was collected and conducted retrospective analysis and correlation evaluation. Pearson's chi-square test was used for correlation analysis of influencing factors, and Kaplan-Meier method was used for survival analysis. Results: A total of 166 patients received 910 times of treatment, with an average of 5.48 times of immune checkpoint inhibitor treatment. A total of 146 cases had adverse events of different degrees, and a total of 462 adverse events were recorded, with an average of 2.78 times/case. The incidence of adverse events was 87.9%. Anemia (78.9%) and leucopenia were the adverse events with a higher proportion (28.9%), neutropenia (18.7%), thrombocytopenia (42.8%), hyperglycemia (21.7%), abnormal thyroid function (9.6%), abnormal cortisol (9.6%), etc. The positive and likely adverse events related to immune checkpoint inhibitors accounted for 11.9% of the total adverse events . There were 22 cases of grade 3 and above adverse events, accounting for 13.2% of the total number of patients. After analysis, whether there are complications of ≥ 3 systems and whether they are combined with other antitumor drugs have a significant impact on the incidence of adverse events. Conclusions: Based on the data of this study, the adverse events of immune checkpoint inhibitors in patients over 75 years old are equivalent to those in patients under 75 years old, and there is no increase in the occurrence of serious adverse events.