This study aims to investigate the constituents of the fruit galls of Actinidium polygama and their anti-inflammatory activity. The methanol extract from the fruit galls of A. polygama was isolated and purified by recrystallization, Sephadex LH-20 column chromatography, silica gel column chromatography, and semi-preparative HPLC. The structure of the compounds were characterized based on their physicochemical properties, NMR and MS data.Thirteen compounds were isolated and identified as 2α,3α,24-trihydroxy-12-ursene-23-al-28-oic acid (1), corosolic acid (2), 2α,3α,24-trihydroxyurs-12,20(30)-dien-28-oic acid (3), 2α,3α,24-trihydroxyolean-12-en-28-oic acid (4), 2α,3α,24-trihydroxyurs-12-en-28-oic acid (5), stigmasterol (6), β-sitosterol (7), ferulic acid (8), caffeic acid (9), protocatechuic acid (10), (+)-(7S,8R)-balanophonin-4-O-β-D-glucopyranoside (11), kaempferol-3-O-β-D-glucopyranoside (12), and quercetin-3-O-β-D-glucopyranoside (13). Except for compound 7, all other compounds were isolated from this species for the first time. Compound 11 was obtained from this Actinidia genus for the first time. The inhibitory effects of the isolated compounds on NO production were evaluated in lipopolysaccharide-stimulated RAW 264.7 macrophages and BV2 microglia cells, using the Griess reaction. The results demonstrated that compound 3 showed no cytotoxicity and significantly reduced NO release in a concentration-dependent manner (P < 0.05 or P < 0.01), with the inhibition were 35.71%, 53.57%, and 74.28% for RAW 264.7 cells and 31.44%, 44.11%, and 60.0% for BV2 cells, showing potential anti-inflammatory activity.