Green tea catechin is known to exhibit various biological functions, and (-)-Epigallocatechin-3-gallate (EGCG) is an active form of a family of various catechins. We examined the effects of EGCG on inflammatory bone resorption, and found that EGCG suppressed the osteoclast formation induced by the toll-like receptor 2 heterodimer, TLR2/6 and TLR2/1 ligands, in co-cultures of mouse bone marrow cells and osteoblasts. Production of prostaglandin E₂ (PGE₂) by osteoblasts is critical for bone resorption associated with inflammation. EGCG acted on osteoblasts and suppressed TLR2/6- and TLR2/1-dependent PGE₂ production and NFκB activation. In mouse calvarial organ cultures, EGCG attenuated the osteoclastic bone resorption elicited by TLR2 heterodimer signaling. Therefore, EGCG might protect against inflammatory bone loss.