Objective:To investigate the correlation between comorbidity and fall injury degree in elderly inpatients with falls.Methods:Using the method of retrospective study, 212 elderly patients with fall comorbidity in a tertiary general hospital from January 2017 to March 2020 were selected as the research objects. The clinical data were collected according to the degree of injury. The severity of comorbidity was evaluated by age adjusted Charlson comorbidity index (ACCI), and the relationship between the comorbidity and the degree of fall injury was analyzed.Results:The overall acci index of 212 patients was (7.21 ± 2.69) points, and the average number of comorbidities was (4.74 ± 2.20). Univariate analysis showed that there were significant differences in CCI ( F value was 10.806, P<0.001)、aCCI ( F value was 15.231, P<0.001), comorbid circulatory system diseases ( χ2 value was 9.580, P=0.022) , urinary system diseases ( χ2 value was 10.127, P=0.018) , endocrine system diseases ( χ2 value was 7.978, P=0.046) and comorbidities( F value was 3.093, P=0.028) among elderly patients with different injury degrees. Spearman correlation analysis showed that age, CCI, aCCI and the number of comorbidities were correlated with the degree of fall injury ( P<0.05). Logistic regression model showed that aCCI ( B value was 0.234, OR value was 1.264) was an independent predictor of fall injury. The area under the ROC curve was 0.652 (95% CI 0.579-0.725, P<0.001). Conclusions:The aCCI index can predict the degree of fall injury.