Objective To analyze the influencing factors of nursing workload in respiratory inpatients, and to investigate the dose-response relationship between nursing workload and Complication and Comorbidity Index (CCI) in respiratory inpatients, in order to provide a reference for clinical patient management and nursing human resource allocation. Methods A total of 1 121 inpatients in the department of respiratory medicine were selected as the study subjects. Their total nursing hours were calculated using the case review method,which entailed the identification of daily nursing care items and the frequency of nursing care.The care provided to the patients during hospitalization was based on the hospital information system's electronic medical records and nursing care execution sheets.The influencing factors of nursing workload were analyzed through multiple linear regression,and the dose-response relationship between the CCI and nursing care workload was explored using the restrictive cubic spline. Results The results of regression analysis showed that, age, admission route, number of hospitalizations, the CCI,use of ventilator,and use of antibiotics were the influencing factors of nursing workload (all P<0.05).The results of restrictive cubic spline showed that, there was a dose-response relationship between the CCI and nursing workload (Poverall trend<0.05, Pnonlinear<0.05),when CCI>0.066,nursing workload increased continuously with the increase of CCI, and group exploration according to different age groups, admission routes,number of hospitalizations,and whether using ventilators and antibiotics showed that,there were significant differences in nursing workload among patients with different clinical characteristics (all P<0.05). Conclusion A dose-response relationship exists between the CCI and nursing workload,which serves as an effective predictor of nursing workload for respiratory inpatients.It is therefore recommended that nursing managers combine patients′ CCI and other clinical characteristics in order to allocate nursing human resources in a scientifically sound manner and thereby improve the efficiency of nursing human resources utilization.