Objective To observe the therapeutic effect of Feiwei Formula（ formula to treat lung wilting） for connective tissue disease-associated interstitial lung disease（ CTD-ILD）. Methods Totally 79 cases of CTD-ILD were randomized into the treatment group and control group

with 40 and 39 in each. The treatment group was given prednisone tablets and Feiwei Formula. The control group was given prednisone only. Both groups were treated for 3 months. The clinical（ C）

radiographic（ R） and physiological（ P） scores and safety indicators were observed before and after treatment in both groups. Results The C

R and P scores were significantly decreased in both groups after treatment（ P < 0. 01）

especially in the treatment group（ P < 0. 01）. There was no obvious abnormality of hepatic function

renal function and ECG in both groups. There were 15 cases of hyperglycemia

8 cases of Cushing syndrome

2 cases of osteoporosis and 1 case of pulmonary infection in the control group

with a side effect rate of 67%. There were 8 cases of hyperglycemia

5 cases of Cushing syndrome

1 case of osteoporosis and 0 case of pulmonary infection in the treatment group

with a side effect rate of 35%. There was a significant difference between groups in the side effect rate（ P < 0. 01）. Conclusion Feiwei Formula can relieve the symptoms and signs of CTD-ILD patients

improve the lung function and radiographic indicators and reduce side effect of prednisone.