A silicone composition for sealing a light emitting element comprising: a vinyl group-containing organopolysiloxane having a three-dimensional network structure represented by an average unit formula: (SiO 4/2) a (ViR 2 SiO 1/2) b (R 3 SiO 1/2) c (where Vi represents a vinyl group, R's are identical or different substituted or unsubstituted monovalent hydrocarbon groups other than alkenyl groups, and a, b, and c are positive numbers satisfying that a/ (a + b + c) is 0.2 to 0.6 and b/(a + b + c) is 0.001 to 0.2); or (A 1) a vinyl group-containing organopolysiloxane having a three-dimensional network structure which is a solid at 25°C and is represented by an average unit formula: (SiO 4/2) a (ViR 2 SiO 1/2) b (R 3 SiO 1/2) c (where Vi represents a vinyl group, R's represent identical or different substituted or unsubstituted monovalent hydrocarbon groups other than alkenyl groups, and a, b, and c are positive numbers satisfying that a/ (a + b + c) is 0.2 to 0.6 and b/ (a + b + c) is 0.001 to 0.2); and (A 2) a straight-chain organopolysiloxane having alkenyl groups whose viscosity at 25°C is 1 to a 100,000 mPa●s, amount of the organopolysiloxane being 10 to 80% by weight of a total amount of the component (A 1) and the component (A 2); and further comprising: an organohydrogenpolysiloxane which has at least two hydrogen atoms, each hydrogen atom being bonded to a silicon atom per molecule, the organohydrogenpolysiloxane being contained in such an amount that the amount of the hydrogen atoms bonded to the silicon atom is 0.3 to 3.0 mol per 1mol of the vinyl group bonded to the silicon atom in the component or the sum of the vinyl group bonded to the silicon atom in the component (A 1) and the alkenyl group bonded to the silicon atom in the component (A 2); a hydrosilylation catalyst (catalytic amount), and a silane coupling agent which is a reaction product of: CH 2 = C(CH 3)COO(CH 2) 3 Si(OCH 3) 3 and an organosiloxane represented by the formula: [(CH 3)HSiO] 3 (CH 3) 2 SiO, wherein the coefficient of linear expansion of the composition after curing is 10 x 10 -6 to 290 X 10 -6 /°C. a vinyl group-containing organopolysiloxane having a three-dimensional network structure represented by an average unit formula: (SiO 4/2) a (ViR 2 SiO 1/2) b (R 3 SiO 1/2) c (where Vi represents a vinyl group, R's are identical or different substituted or unsubstituted monovalent hydrocarbon groups other than alkenyl groups, and a, b, and c are positive numbers satisfying that a/ (a + b + c) is 0.2 to 0.6 and b/(a + b + c) is 0.001 to 0.2); or (A 1) a vinyl group-containing organopolysiloxane having a three-dimensional network structure which is a solid at 25°C and is represented by an average unit formula: (SiO 4/2) a (ViR 2 SiO 1/2) b (R 3 SiO 1/2) c (where Vi represents a vinyl group, R's represent identical or different substituted or unsubstituted monovalent hydrocarbon groups other than alkenyl groups, and a, b, and c are positive numbers satisfying that a/ (a + b + c) is 0.2 to 0.6 and b/ (a + b + c) is 0.001 to 0.2); and (A 2) a straight-chain organopolysiloxane having alkenyl groups whose viscosity at 25°C is 1 to a 100,000 mPa●s, amount of the organopolysiloxane being 10 to 80% by weight of a total amount of the component (A 1) and the component (A 2); and further comprising: an organohydrogenpolysiloxane which has at least two hydrogen atoms, each hydrogen atom being bonded to a silicon atom per molecule, the organohydrogenpolysiloxane being contained in such an amount that the amount of the hydrogen atoms bonded to the silicon atom is 0.3 to 3.0 mol per 1mol of the vinyl group bonded to the silicon atom in the component or the sum of the vinyl group bonded to the silicon atom in the component (A 1) and the alkenyl group bonded to the silicon atom in the component (A 2); a hydrosilylation catalyst (catalytic amount), and a silane coupling agent which is a reaction product of: CH 2 = C(CH 3)COO(CH 2) 3 Si(OCH 3) 3 and an organosiloxane represented by the formula: [(CH 3)HSiO] 3 (CH 3) 2 SiO, wherein the coefficient of linear expansion of the composition after curing is 10 x 10 -6 to 290 X 10 -6 /°C. CH 2 = C(CH 3)COO(CH 2) 3 Si(OCH 3) 3 and an organosiloxane represented by the formula: [(CH 3)HSiO] 3 (CH 3) 2 SiO, wherein the coefficient of linear expansion of the composition after curing is 10 x 10 -6 to 290 X 10 -6 /°C.