An addition one part curing type heat-conductive silicone grease composition capable of being stored at normal temperature, the composition comprising, 100 parts by weight of an organopolysiloxane containing at least one alkenyl group per molecule and having a viscosity of 50 mPa·s to 100,000 mPa·s at 25°C as measured by a rotational viscometer; an organohydrogenpolysiloxane which contains at least two silicon-bonded hydrogen atoms per molecule, which has no R 2 SiO unit (where R independently represents an unsubstituted or substituted monovalent hydrocarbon group), which has no silicon-bonded hydrogen atom at any terminal end, which has the silicon-bonded hydrogen atoms only in a side chain or chains, and which is in a substantially straight chain form, in an amount such that the ratio of {the number of Si-H groups}/{the number of alkenyl groups in the composition} is in the range from 0.1 to 5.0; a photoactive type platinum complex curing catalyst selected from the group consisting of trimethyl(acetylacetonato)platinum complex, platinum trimethyl(2,4-pentanedionate) complex, platinum trimethyl(3,5-heptanedionate) complex, platinum trimethyl(methylacetoacetate) complex, bis(2,4-pentanedionato)platinum complex, bis(2,4-hexanedionato)platinum complex, bis(2,4-heptanedionato)platinum complex, bis(3,5-heptanedionato)platinum complex, bis(1-phenyl-1,3-butanedionato)platinum complex, bis(1,3-diphenyl-1,3-propanedionato)platinum complex, (1,5-cyclooctadienyl)dimethyl platinum complex, (1,5-cyclooctadienyl)diphenyl platinum complex, (1,5-cyclooctadienyl)dipropyl platinum complex, (2,5-norboradiene)dimethyl platinum complex, (2,5-norboradiene)diphenyl platinum complex, (cyclopentadienyl)dimethyl platinum complex, (methylcyclopentadienyl)diethyl platinum complex, (trimethylsilylcyclopentadienyl)diphenyl platinum complex, (methylcycloocta-1,5-dienyl)diethyl platinum complex, (cyclopentadienyl)trimethyl platinum complex, (cyclopentadienyl)ethyldimethyl platinum complex, (cyclopentadienyl)acetyldimethyl platinum complex, (methylcyclopentadienyl)trimethyl platinum complex, (methylcyclopentadienyl)trihexyl platinum complex, (trimethylsilylcyclopentadienyl)trimethyl platinum complex, (dimethylphenylsilylcyclopentadienyl)triphenyl platinum complex, and (cyclopentadienyl)dimethyltrimethylsilylmethyl platinum complex, in an effective amount; and 100 to 20,000 parts by weight of a heat-conductive filler selected from aluminum powder, copper powder, silver powder, nickel powder, gold powder, alumina powder, zinc oxide powder, magnesium oxide powder, aluminum nitride powder, boron nitride powder, silicon nitride powder, diamond powder, and carbon powder said heat-conductive filler having a thermal conductivity of at least 10 W/m·°C, wherein the composition has a viscosity at 25°C of 30 Pa·s to 800 Pa·s as measured by a Malcom viscometer at a rotational speed of 10 rpm. 100 parts by weight of an organopolysiloxane containing at least one alkenyl group per molecule and having a viscosity of 50 mPa·s to 100,000 mPa·s at 25°C as measured by a rotational viscometer; an organohydrogenpolysiloxane which contains at least two silicon-bonded hydrogen atoms per molecule, which has no R 2 SiO unit (where R independently represents an unsubstituted or substituted monovalent hydrocarbon group), which has no silicon-bonded hydrogen atom at any terminal end, which has the silicon-bonded hydrogen atoms only in a side chain or chains, and which is in a substantially straight chain form, in an amount such that the ratio of {the number of Si-H groups}/{the number of alkenyl groups in the composition} is in the range from 0.1 to 5.0; a photoactive type platinum complex curing catalyst selected from the group consisting of trimethyl(acetylacetonato)platinum complex, platinum trimethyl(2,4-pentanedionate) complex, platinum trimethyl(3,5-heptanedionate) complex, platinum trimethyl(methylacetoacetate) complex, bis(2,4-pentanedionato)platinum complex, bis(2,4-hexanedionato)platinum complex, bis(2,4-heptanedionato)platinum complex, bis(3,5-heptanedionato)platinum complex, bis(1-phenyl-1,3-butanedionato)platinum complex, bis(1,3-diphenyl-1,3-propanedionato)platinum complex, (1,5-cyclooctadienyl)dimethyl platinum complex, (1,5-cyclooctadienyl)diphenyl platinum complex, (1,5-cyclooctadienyl)dipropyl platinum complex, (2,5-norboradiene)dimethyl platinum complex, (2,5-norboradiene)diphenyl platinum complex, (cyclopentadienyl)dimethyl platinum complex, (methylcyclopentadienyl)diethyl platinum complex, (trimethylsilylcyclopentadienyl)diphenyl platinum complex, (methylcycloocta-1,5-dienyl)diethyl platinum complex, (cyclopentadienyl)trimethyl platinum complex, (cyclopentadienyl)ethyldimethyl platinum complex, (cyclopentadienyl)acetyldimethyl platinum complex, (methylcyclopentadienyl)trimethyl platinum complex, (methylcyclopentadienyl)trihexyl platinum complex, (trimethylsilylcyclopentadienyl)trimethyl platinum complex, (dimethylphenylsilylcyclopentadienyl)triphenyl platinum complex, and (cyclopentadienyl)dimethyltrimethylsilylmethyl platinum complex, in an effective amount; and 100 to 20,000 parts by weight of a heat-conductive filler selected from aluminum powder, copper powder, silver powder, nickel powder, gold powder, alumina powder, zinc oxide powder, magnesium oxide powder, aluminum nitride powder, boron nitride powder, silicon nitride powder, diamond powder, and carbon powder said heat-conductive filler having a thermal conductivity of at least 10 W/m·°C, wherein the composition has a viscosity at 25°C of 30 Pa·s to 800 Pa·s as measured by a Malcom viscometer at a rotational speed of 10 rpm.