Abstract: The objective of this research is to investigate the anti-inflammatory mechanism of Physalis alkekengi. Anti-inflammatory and analgesic effects of Physalis alkekengi calyx extracts were observed by means of carrageenan induced paw edema model, granuloma model and acetic acid writhing test. Rats and mice were divided into four groups randomly as followed: model control group, indomethacin group, Physalis alkekengi calyx extracts high and low dose groups. The foot swelling degree of rats, thymus index, spleen index, the weight of granuloma and the body torsion of mice were observed. The concentrations of PLA₂, 5-LOX, COX-2, PGE₂ and LTB₄ in serum were measured. The results showed that Physalis alkekengi calyx extracts could inhibit acute inflammation and chronic inflammation significantly. Meanwhile, Physalis alkekengi calyx extracts showed a certain protective effect on immune organs and could reduce the contents of PLA₂, COX-2, PGE₂, 5-LOX and LTB₄ in serum in different degrees. The results obtained here showed that Physalis alkekengi calyx extracts might be a dual inhibitor to inhibit AA metabolic pathways by inhibiting the activity of the enzyme COX-2 and 5-LOX oxidation.