AVLP-2, a novel acidic polysaccharide, was isolated and purified from Amomum villosum Lour. The structural characteristics of the polysaccharides were characterized using monosaccharide composition, methylation, FT-IR, and NMR techniques. Results showed that AVLP-2 comprises galactose and glucose monomers, has a molecular weight of 10.488 kDa, and has backbone structures ?4)-?-D-GalAp-(1?3,4)-?-D-GalAp-(1?, ?4)-?-D-GalAp-(1?6)-?-D-Galp-(1?, and n?6)-?-D-Galp-(1?4)-?-D-Glcp-(1?, with ?-D-Galp-(1? branches. Furthermore, AVLP-2 had a significant protective effect against oxidative stress in alcohol-induced injury and LPS inflammation models GES-1 cells by regulating the levels of ROS and inflammatory factors. In the animal experiments, AVLP-2 improved the oxidative stress status of the gastric mucosa by increasing SOD activity and GSH levels and inhibiting the excessive generation of malondialdehyde in tissues. The levels of MPO, IL-1?, IL-10, and NF-?B p65 were downregulated, while that of TNF-? was upregulated by AVLP-2 treatment, thereby reducing the alcohol-induced inflammation.