Abstract： Objective:To explore the diaphragmatic structure and kinematic characteristic by using ultrasound and its correlation with pulmonary function in stroke tracheotomy patients and evaluate the application value of predicting pulmonary function by using ultrasonography parameters of diaphragm.Methods:Forty patients with stroke tracheotomy admitted to the Rehabilitation Medicine Department of People's Hospital of Xinjiang Uygur Autonomous Region from January 2020 to November 2023 were selected as the tracheostomy group, and 40 healthy subjects who underwent physical examinations during the same period were selected as the control group. All subjects underwent pulmonary function assessment and diaphragmatic ultrasound examination. The forced vital capacity (FVC), forced expiratory volume in one second (FEV1.0), FEV1.0/FVC, end-expiratory diaphragm thickness (EDT), end-inspiration diaphragm thickness (IDT), diaphragm thickening fraction (DTF) and diaphragm mobility were used as outcome measures. The correlation of pulmonary function with ultrasonography parameters of diaphragm were analyzed.Results:Compared with the control group, the tracheotomy group had significantly greater decreased on FVC, FEV1.0/FVC, EDT, IDT, DTF and diaphragm mobility (all P<0.05). The FVC were significantly positively correlated with EDT (r=0.949, P<0.05), IDT (r=0.973, P<0.05), DTF (r=0.974, P<0.05) and diaphragm mobility (r=0.978, P<0.05). The FEV1.0/FVC were significantly positively correlated with EDT (r=0.961, P<0.05), IDT (r=0.971, P<0.05), DTF (r=0.968, P<0.05) and diaphragm mobility (r=0.979, P<0.05).Conclusion:The pulmonary function improves along with the diaphragm aticstructure and function improves in stroke tracheotomy patients. The ultrasonography parameters of diaphragm can predict the pulmonary function.