A pharmaceutical composition is provided, where the pharmaceutical composition contains formula (I), (II), or (III) flavonoids which possess selective phosphodiesterase 4 or 4/3 inhibition, as a main ingredient. Especially, this composition is used in the treatment of asthma, chronic obstructive pulmonary disease (COPD), or chronic inflammation, and has bronchodilatory effects. In addition, whether the above-mentioned flavonoids have side effects, such as nausea, vomiting, gastric hypersecretion, etc., in accordance with their binding to high affinity rolipram binding sites (HARBS) of particulates of brain cells are disclosed.