Abstract: Disclosed in the present invention are polymorphic forms of a compound and a preparation method therefor and an application thereof. A crystal form III of a compound A uses Cu—K? radiation, and X-ray powder diffraction expressed at 2? angles has characteristic peaks at 12.15±0.20°, 15.98±0.20°, 16.62±0.20°, 17.14±0.20°, 24.32±0.20°, and 26.08±0.20°. A crystal form VII of the compound A uses Cu—K? radiation, and X-ray powder diffraction expressed at 2? angles has characteristic peaks at 12.94±0.20°, 14.41±0.20°, 15.64±0.20°, 17.25±0.20°, 21.75±0.20°, and 24.23±0.20°. The polymorphic forms prepared by the present invention are good in stability, and can be stably stored under the conditions of high temperature and low relative humidity.

Abstract: A medicine for treating allergic cough comprises 5 to 25 parts by weight of Perilla Leaf, 5 to 25 parts by weight of Periostracum Cicada, and 5 to 25 parts by weight of lumbricus. The medicine is in the form of concentrated decoction, tablet, pill, granule or capsule. The medicine has effects of dispelling wind-cold, dispelling wind-heat, relieving cough and preventing asthma. The medicine provides excellent anti-allergic effect and can be used for treating allergic cough.

Abstract: A medicine for treating allergic cough comprises 5 to 25 parts by weight of Perilla Leaf, 5 to 25 parts by weight of Periostracum Cicada, and 5 to 25 parts by weight of lumbricus. The medicine is in the form of concentrated decoction, tablet, pill, granule or capsule. The medicine has effects of dispelling wind-cold, dispelling wind-heat, relieving cough and preventing asthma. The medicine provides excellent anti-allergic effect and can be used for treating allergic cough.