Because antioxidants from natural sources may be an effective approach to the treatment and prevention ofUVradiation‐induced skin damage, the effects of purified exopolymers fromAureobasidium pullulansSM‐2001 (‘E‐AP‐SM2001’) were evaluated inUVB‐induced hairless mice. E‐AP‐SM2001 consists of 1.7% β‐1,3/1,6‐glucan, fibrous polysaccharides and other organic materials, such as amino acids, and mono‐ and di‐unsaturated fatty acids (linoleic and linolenic acids) and shows anti‐osteoporotic and immunomodulatory effects, through antioxidant and anti‐inflammatory mechanisms. Hairless mice were treated topically with vehicle, E‐AP‐SM2001 stock and two and four times diluted solutions once per day for 15 weeks againstUVBirradiation (three times per week at 0.18 J/cm2). The following parameters were evaluated in skin samples: myeloperoxidase (MPO) activity, cytokine levels [interleukin (IL)‐1β andIL‐10], endogenous antioxidant content (glutathione,GSH), malondialdehyde (MDA) levels, superoxide anion production; matrix metalloproteases (MMP‐1, ‐9 and ‐13),GSHreductase and Nox2 (gp91phox)mRNAlevels, and immunoreactivity for nitrotyrosine (NT), 4‐hydroxynonenal (HNE), caspase‐3, and cleaved poly(ADP‐ribose) polymerase (PARP). Photoageing was induced byUVBirradiation throughROS‐mediated inflammation, which was related to the depletion of endogenous antioxidants, activation ofMMPs and keratinocyte apoptosis. Topical treatment with all three doses of E‐AP‐SM2001 and 5 nmmyricetin attenuated theUV‐induced depletion ofGSH, activation ofMMPs, production ofIL‐1β, the decrease inIL‐10 and keratinocyte apoptosis. In this study, E‐AP‐SM2001 showed potent inhibitory effects againstUVB‐induced skin photoageing. Thus, E‐AP‐SM2001 may be useful as a functional ingredient in cosmetics, especially as a protective agent againstUVB‐induced skin photoageing.