1. Yunaconitine (Guayewuanine B) has anti-inflammatory and analgesic actions. 2. Yunaconitine was shown to have anti-thermic effect in pyrexial rats when administered orally at a dose of 5 μg/kg. 3. Yunaconitine shows positive effect in the granuloma inhibition test when it was subcutaneously injected, 1 μg/kg for 6 d, or added directly to the cotton-pellet. 4. Yunaconitine inhibited the increased vascular permeability caused byacetic acid and histamine, the leucocyte migratory response induced by injection of 1 % carrageenin .1 ml in rat's thoracic cavity.