Abstract: Paonangcao (Physochlaina physaloides (L.) G. Don) is a wild plant. Its root contains anisodamine which is used for the treatment of septic shock from toxic bacillary dysentery, fulminant epidemic meningitis, etc. The seeds studied were collected from the Inner Mongolia Autonomous Region, and the work was carried out from 1966 to 1969. Our experiments indicated that the seeds must be treated by low temperature, the seeds were embedded 5～10 cm underground in early winter to keep the temperature at about —11℃, or they will fail to germinate in the following spring. The seeds were sowed as soon as they were dug out and begun to bud at about the 17th day after sowing. The anisodamine content in the root was 0.025～0.229%. The dried root of the 2-year crop per plant weighed 45.8 g on average, with a maximum 110 g, while that of the 1-year plant weighed 12.0 g, with a maximum 23.1 g. The seeds harvested from the 2-year plants yielded on the average 2545 grains per plant. A thousand seeds weighed 4.26～4.50 g.This paper also reports the biological characteristics of the growth, bloom, fructication, summer dormancy and observations on the phenological phases of this plant.