The anti-inflammatory effect of total phenolics from Laggera alata (TPLA) was evaluated with various in vivo models of both acute and chronic inflammations. In the acute inflammation tests, TPLA inhibited significantly xylene-induced mouse ear oedema, carrageenan-induced rat paw oedema and acetic acid-induced mouse vascular permeability. In the carrageenan-induced rat pleurisy model, TPLA significantly suppressed inflammatory exudate and leukocyte migration, reduced the serum levels of lysozyme (LZM) and malondialdehyde (MDA), increased the serum levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX), and also decreased the contents of total protein, nitric oxide (NO) and prostaglandin E(2) (PGE(2)) in the pleural exudates. In the chronic inflammation experiment, TPLA inhibited significantly cotton pellet-induced rat granuloma. These results indicated that TPLA possesses potent anti-inflammatory activity on acute and chronic inflammation models. Its anti-inflammatory mechanisms are probably associated with the inhibition of prostaglandin formation, the influence on the antioxidant systems, and the suppression of LZM release. Furthermore, the total phenolic content of Laggera alata and its main component type was quantified, and its principle components were isolated and authenticated. Acute toxicity studies revealed that TPLA up to an oral dose of 8.5 g/kg body weight was almost nontoxic in mice.