ObjectiveTo investigate the molecular mechanism of the anti-inflammatory effect of Erchentang in the lung tissue of the rat model of chronic obstructive pulmonary disease （COPD） via the heparin-binding factor （Midkine）/transmembrane receptor protein （Notch2）/Hey1 signaling pathway. MethodSixty SD rats were randomized into normal group， model group， modified Erchentang （5， 10， 20 g·kg-1·d-1） groups， and Notch1 pathway inhibitor （γ-secretase inhibitor， DAPT， 0.02 g·kg-1） group， with 10 rats in each group. The rat model of COPD was established by cigarette smoke combined with lipopolysaccharide （LPS）. After the modeling， the rats were administrated with corresponding drugs by gavage， and those in the normal and model groups were administrated with normal saline by gavage for 21 days. The levels of Midkine， cytokine-induced neutrophil chemoattractant-1 （CINC-1）， macrophage-derived chemokine （MDC）， chemokine ligand 5 （CXCL5）， neutrophil elastase （NE）， and nuclear factor-kappa B （NF-κB） p65 in bronchoalveolar lavage fluid （BALF） were determined by enzyme-linked immunosorbent assay （ELISA）. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） and immunohistochemistry were respectively employed to determine the mRNA and protein levels of Midkine， Notch2， and Hey1 in the lung tissue. ResultCompared with the normal group， the modeling increased the levels of Midkine， CINC-1， MDC， CXCL5， NE， and NF-κB p65 in BALF （P<0.01） and up-regulated the mRNA and protein levels of Midkine， Notch2， and Hey1 in the lung tissue （P<0.01）. Compared with the model group， medium- and high-dose modified Erchentang and DAPT lowered the levels of Midkine， CINC-1， MDC， CXCL5， and NF-κB p65 in BALF （P<0.01） and down-regulated the mRNA levels of Midkine， Notch2， and Hey1 （P<0.01）. ConclusionModified Erchentang may inhibit the inflammation in COPD rats by down-regulating the expression of Midkine， Notch2， and Hey1 and reducing the content of Midkine， CINC-1， MDC， and CXCL5.