Amygdalin is an effective component in bitter almond for relieving cough and asthma. Amygdalin is not only contained in bitter almond, but also has an enzyme that can decompose amygdalin. This enzyme can be activated under certain temperature and humidity to decompose amygdalin and produce hydrocyanic acid. Therefore, excessive or raw eating can cause hydrocyanic acid poisoning and inhibit cell respiration, The formation of "intracellular asphyxia" tissue hypoxia. After oral administration, amygdalin can be decomposed into hydrocyanic acid and benzaldehyde in the body. Hydrocyanic acid can produce a certain inhibitory effect on the respiratory center, and make the respiratory movement tend to be quiet, so as to achieve the effect of antitussive and antiasthmatic.