Abstract: The invention discloses an application of phlegmyheatclear in preparation of a drug for treatment of acute exacerbation of chronic obstructive pulmonary disease. The present invention studies the effect of phlegmyheatclear on model of rats with acute exacerbation of chronic obstructive pulmonary disease. Results show that high dose, middle dose, or low dose of phlegmyheatclear can, during the acute exacerbation of chronic obstructive pulmonary disease, improve the lung function of the rats and the pathological damage of lung tissues of the rats in different degrees, and it is dose dependent. High dose, middle dose, or low dose of phlegmyheatclear can improve inflammatory reaction in different degrees. For the drug effects, the high dose and the middle dose of phlegmyheatclear are better than the low dose of phlegmyheatclear. Therefore, phlegmyheatclear can be used to prepare a drug for treatment of acute exacerbation of chronic obstructive pulmonary disease.