Objective: To observe the effect of Gualou Xiebai decoction to pathological lesion and dopamine(DA)

norepinephrine(NE)

5-hydroxytryptamine(5-HT)in lung at stage of pulmonary fibrosis formation in rats. Method :The female Wistar rats were divided into control

model

prednisone and Gualou Xiebai decoction groups randomly. The model was induced by injected pingyangmycin in trachea only once. The drugs were used after 14 days as treatments. After 28 days of the model establishment

the rats were sacrificed. The lung index

pulmonary fibrosis degree

contents of DA

NE and 5-HT in lung tissue were evaluated and compared. Result: The pulmonary fibrosis degree was obviously severe in model than other groups(P<0.05)and the lung index was high in the model than other groups(P<0.05). The contents of DA

NE and 5-HT in lung tissue were obviously high in the model compared with the control and prednisone groups(P<0.05). The contents of NE were obviously high than that in model group

but contents of DA and 5-HT were lower in Gualou Xiebai decoction than model group(P<0.05). Conclusion: Gualou Xiebai decoction had the function to lessen lung pathology change in pulmonary fibrosis formation stage. The DA

NE and 5-HT were high in the pulmonary fibrosis formation stage. Gualou Xiebai decoction had the function to restrain the increase in DA and 5-HT and raise the NE content in model lung.