Linaggrenoid A (1), a highly rearranged lindenane sesquiterpenoid, together with eight undescribed lindenane sesquiterpenoid linaggrenoids B-I (2-9) and eight known analogs (10-17), were isolated from the root tubers of Lindera aggregata. Their structures, including absolute configurations, were established using spectroscopic and computational methods, as well as single-crystal X-ray diffraction. Linaggrenoids A and H (1 and 8), featuring a 5/6/3 and 3/5/6 carbocyclic ring system, respectively, demonstrated potential as anti-hepatic fibrosis agents by suppressing the expression of fibronectin, collagen I, and α-smooth muscle actin in TGF-β1-induced LX-2 cells.