Objective To observe clinical efficacy of Yangyin Yiqi Mixture（ 养阴益气合剂） patients of idiopathic pulmonary fibrosis with deficiency of both Qi and Yin syndrome. Methods Eighty-four patients were randomly divided into test group and control group

42 cases in each group. The test group orally took Yangyin Yiqi Mixture

3times a day

20 ml per time. The control group orally took dexamethasone acetate tablets. If patients had not taken hormone before entering the control

they took orally dexamethasone acetate

0. 5 mg / kg per day for four weeks and changed to 0. 25 mg / kg per day from the 5th week to the 13 th week

then reduced to 0. 125 mg / kg per day

once a day and were given the maintenance treatment. If patients had been taking hormone before entering the control group

they went on taking the current dose and the reduction method was the same as above. Course of treatment was 3months. Measured pulmonary function indexes including forced expiratory volume in one second（ FEV1）

percentage of FEV1 account for predicted value（ FEV1 %） and FEV1 / forced vital capacity（ FVC） of two groups before and after treatment and conduct 6 minutes walk test. Evaluated quality of life of patients according to the St. George’ s respiratory questionnaire（ SGRQ） and estimated the clinical efficacy after treatment. Results The total effective rate was 66. 7% and 42. 9% in the test group and the control group respectively. The total effective rate of the test group was higher than that of the control group（ P < 0. 05）. After treatment

SGRQ scores in both groups were significantly lower than those before treatment（ P < 0. 05） and SGRQ scores in the test group was significantly lower than those in the control group（ P < 0. 05）. After treatment

6 minutes walking distance and levels of FEV1

FEV1%

FEV1 / FVC in the two groups were significantly higher than those before treatment（ P < 0. 05 or P < 0. 01）. After treatment

6 minutes walking distance and levels of FEV1

FEV1%

FEV1 / FVC in the test group were significantly higher than those in the control group（ P < 0. 05 or P < 0. 01）. Conclusion Yangyin Yiqi Mixture has definite therapeutic effect on patients of idiopathic pulmonary fibrosis with deficiency of both Qi and Yin syndrome. It can effectively improve the clinical symptoms

protect pulmonary function and improve quality of life of the patients.