The extract of Siegesbeckiae herba of the present invention showed potent inhibitory effect on the dissociation of proteoglycan and type II collagen in chondrocyte and cartilage tissue and protecting effect on cartilage due to the inhibition of MMP-1, MMP-3 and MMP-13 activity and the restoring effect on cartilage tissue, the anti-inflammatory and antiphlogistic effect in edema animal model, anti-inflammatory effect confirmed by the inhibition test on PGE2 activity through COX-2 inhibition and the inhibition test of the reproduction of TNF-.alpha. and NO, it can be used as the therapeutics or health food for treating and preventing arthritic disease.