Herein, a water-soluble Ganoderma tsugae acidic polysaccharide (GTP-2) was isolated and purified from the fruiting bodies of G. tsugae. GTP-2 has a molecular weight of 13.059 kDa, composed of →3)-β-d-Glcp-(1 → 3)-β-d-Glcp-(1 → 4)-GlcpUA-(1 → 4)-β-d-Glcp-1→ glucan backbone and branches ending with β-d-Glcp-(1 → 6)-β-d-Glcp-(1→, which is attached at C6 of →3,6)-β-d-Glcp-(1→. Subsequently, the antiatherosclerotic activity of GTP-2 was examined in apolipoprotein E deficient (ApoE