Objective:To observe the effect of Yuxing Dilong decoction on smoking cession and chronic obstructive pulmonary diseases（COPD）.Methods:Forty male Kunming mice were equally and randomly divided into four groups:normal control group

nicotine dependence model group

drug therapy group of low

middle

high dose.The experimental nicotine dependence rat model was made by subcutaneous injection of nicotin.At the same time

the low

middle and high dose groups were treated Yuxing Dilong decoction[(6.11 g/（kg·d）

12.22 g/（kg·d）

24.44 g/（kg·d）] for two weeks.The nicotine withdrawal symptoms and the level of dopamine（DA）in the striatum in each group were observed.Forty male Sprague Dawley rats were equally and randomly divided into four groups :normal control group

COPD model group

drug therapy group of low

middle

high dose.The experimental COPD rat model was made by intraperitoneal injection of cigarette smoke extract.At the same time

the low

middle and high dose groups were treated with Yuxing Dilong decoction[4.23 g/（kg·d）

8.46 g/（kg·d）

16.92 g/（kg·d）] for three weeks.The pathological changes and the levels of interleukin-8（IL-8）and tumor necrosis factor alpha（TNF-α）of lung tissue in rats were detected.Results:（1）In the nicotine addiction model

compared with the model group

the middle

high dose Yuxing Dilong decoction can significantly increase the number of crossing squares（P=0.005

P=0.003）

and the low

middle and high dose Yuxing Dilong decoction can significantly reduce the times of body erection（P=0.04

P=0.03

P=0.001）

the high dose Yuxing Dilong decoction can significantly reduce the swimming immobility（P=0.034）;the middle

high dose Yuxing Dilong decoction can significantly reduce the level of DA（P=0.05

P=0.004）.（2）In the COPD model

the alveolus in the COPD rats was damaged obviously and the infiltration of inflammatory cells was observed.Compared with the model group

low

middle and high dose Yuxing Dilong decoction can reduce the mean linear intercept（MLI）（P=0.003

P=0.000

P=0.000）;Middle and high dose Yuxing Dilong decoction can reduce the destructive index（DI）（P=0.000

P=0.000）.Enzyme-linked immunosorbent assay analysis showed that compared with the model group

the low

middle and high doses Yuxing Dilong decoction can reduce the levels of IL-8 in lung tissue（P=0.002

P=0.001

P=0.000）and the level of TNF-α in lung tissue（P=0.022

P=0.005

P=0.000）.Conclusion:Yuxing Dilong decoction may alleviate the nicotine withdrawal symptoms by increasing the concentration of dopamine in the striatum

and improve the pathological changes of the lung tissue by reducing the level of inflammatory cytokinesnot

which is hoped to provide new experimental data for the treatment of smoking cessation.