Artemisia capillaris Thunb. from Asteraceae revealed remarkable early-stage anti-gastritis ability and anti-chronic gastritis and anti-precancerous lesion capacity by down-regulating IL-1β, IL-6, TNF-α, COX-2, PGE2, gastric F4/80 protein, and MDA with low p-p65 and pSTAT3 expression. This evidence concerns the gene PTGS2 and gastritis.