TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The adhesive composition contains ultraviolet stabilizer of 0.01-0.5 weight parts, crosslinking agent of 0.05-2weight parts and thermal initiator of 0.01-2 weight parts with respect to acrylic resin of 100 weight parts. Preferred Method: The acrylic resin is obtained by polymerizing (meth)acrylic acid ester monomer and copolymer of polar monomer. Preferred Components: The acrylic resin contains 1-12C alkyl groups. The (meth)acrylic acid ester monomer is butyl(meth)acrylate, hexyl(meth)acrylate, N-octyl(meth)acrylate, isooctyl(meth)acrylate, 2-ethylhexyl(meth)acrylate and/or isononyl(meth)acrylate. The polar monomer is carboxyl group-containing monomer and/or nitrogen-containing monomer. The ultraviolet stabilizer is metal deactivator, thermal stabilizer, ultraviolet absorbing agent, quencher, peroxide decomposer, radical scavenger and/or hindered amine light stabilizers. The thermal initiator is 2,2'-azobis(iso butyronitrile), 2,2'-azobis(2-methyl butyronitrile), 2,2'-azobis(2,4-dimethyl valeronitrile), 2,2'-azobis(4-methoxy-2,4-dimethyl valeronitrile), 4,4'-azobis(4-dimethyl valeronitrile), 2,2'-azobis(2-methyl-N-(1,1-bis)(hydroxymethyl)-2-hydroxyethyl)propionamide, 2,2'-azobis(2-methyl-N-2-(1-hydroxybutyl))propionamide, dilauryl peroxide, dibenzoyl peroxide, tert-butyl peroxy neodecanoate, tert-amylperoxy pivalate, di(2-ethylhexyl)peroxy dicarbonate, di(3-methoxy butyl) peroxy dicarbonate, 3-hydroxy-1,1-dimethyl butyl peroxy neodecanoate, di(3,5,5-trimethylhexanoyl)peroxide, tert-amylperoxy-2-ethyl hexanoate, tert-butyl peroxy-2-ethyl hexanoate, tert-butyl isopropyl mono peroxycarbonate, tert-butylperoxy-2-2ethylhexyl carbonate, dibenzoyl peroxide, tert-amyl(2-ethylhexyl)mono peroxycarbonate, tert-butylperoxy isopropyl carbonate, tert-butyl peroxybenzoate or 1,1,3,3-tetramethylbutyl peroxy neodecanoate. The crosslinking agent is 1,6-hexanediol diacrylate, trimethyl propane triacrylate, pentaerythritol triacrylate, 1,2-ethylene glycol diacrylate and/or 1,12-dodecanediol acrylate. The adhesive sheet has tackifier layer and substrate sheet. The substrate sheet is plastic film, paper, non-woven fabrics, glass or metal. The plastic film is polyethylene terephthalate film. Preferred Property: The optical transmittance rate in the hardened state is 20% or more in ultraviolet-A domain, 60% or more in ultraviolet-B domain and 40% or more in ultraviolet-C domain. The yellowing rate in the hardened state is 30% than in 24 time exposure under ultraviolet ray. The thickness of the adhesive sheet is 50 mu m or 2 nm. EXAMPLE - 2-ethyl acrylate (in weight parts) (95), acrylic acid (5), Cyabsorb UV-9 (RTM: benzophenone-type ultraviolet absorber) (0.1), benzoyl peroxide (0.5) and 1,6 hexanediol diacrylate (0.05) were mixed, to obtain adhesive composition. The adhesive composition was formed to a film having thickness of 0.4 mm. The obtained film had excellent weather resistance and durability.