A heat conductive silicone grease composition, consisting of: 100 parts by volume of an organopolysiloxane represented by a general formula shown below: wherein, each R 1 represents, independently, an unsubstituted or substituted monovalent hydrocarbon group, each R 2 represents, independently, an alkyl group, alkoxyalkyl group, alkenyl group or acyl group, a represents an integer from 5 to 100, and b represents an integer from 1 to 3, with a kinematic viscosity at 25°C of 10 to 10,000 mm 2 /s, 0.1 to 50 parts by volume of an alkoxysilane represented by a general formula shown below: R 3 c R 4 d Si(OR 5) 4-c-d wherein, each R 3 represents, independently, an alkyl group of 9 to 15 carbon atoms, each R 4 represents, independently, an unsubstituted or substituted monovalent hydrocarbon group of 1 to 8 carbon atoms, each R 5 represents, independently, an alkyl group of 1 to 6 carbon atoms, c represents an integer from 1 to 3, and d represents an integer from 0 to 2, provided that c+d represents an integer from 1 to 3, and 100 to 2,500 parts by volume of a heat conductive filler consisting of aluminum, zinc oxide, or a combination thereof, and having an average particle size of 0.1 to 50 μm determined by using a laser diffraction method to determine a volume-based cumulative average particle size; and optionally component; component; fluorine-modified silicone surfactants; colorants selected from carbon black, titanium dioxide and red iron oxide; flame retardancy-imparting agents selected from platinum catalysts, metal oxides selected from iron oxide, titanium oxide and cerium oxide, and metal hydroxides; a finely powdered silica selected from a precipitated silica or calcined silica, and/or a thixotropic improvement agent, wherein component is an organopolysiloxane represented by an average composition formula shown below: R 6 e SiO (4-e)/2 wherein, each R 6 represents, independently, an unsubstituted or substituted monovalent hydrocarbon group of 1 to 18 carbon atoms, and e represents a number from 1.8 to 2.2, with a kinematic viscosity at 25°C of 10 to 100,000 mm 2 /s, and component is a volatile solvent capable of dissolving or dispersing said components and, in a quantity not greater than 100 parts by volume per 100 parts by volume of said component wherein the component is toluene, xylene, acetone, methyl ethyl ketone, cyclohexanone, n-hexane, n-heptane, butanol, isopropanol, and isoparaffin-based solvents, or a combination thereof. 100 parts by volume of an organopolysiloxane represented by a general formula shown below: wherein, each R 1 represents, independently, an unsubstituted or substituted monovalent hydrocarbon group, each R 2 represents, independently, an alkyl group, alkoxyalkyl group, alkenyl group or acyl group, a represents an integer from 5 to 100, and b represents an integer from 1 to 3, with a kinematic viscosity at 25°C of 10 to 10,000 mm 2 /s, 0.1 to 50 parts by volume of an alkoxysilane represented by a general formula shown below: R 3 c R 4 d Si(OR 5) 4-c-d wherein, each R 3 represents, independently, an alkyl group of 9 to 15 carbon atoms, each R 4 represents, independently, an unsubstituted or substituted monovalent hydrocarbon group of 1 to 8 carbon atoms, each R 5 represents, independently, an alkyl group of 1 to 6 carbon atoms, c represents an integer from 1 to 3, and d represents an integer from 0 to 2, provided that c+d represents an integer from 1 to 3, and 100 to 2,500 parts by volume of a heat conductive filler consisting of aluminum, zinc oxide, or a combination thereof, and having an average particle size of 0.1 to 50 μm determined by using a laser diffraction method to determine a volume-based cumulative average particle size; and optionally component; component; fluorine-modified silicone surfactants; colorants selected from carbon black, titanium dioxide and red iron oxide; flame retardancy-imparting agents selected from platinum catalysts, metal oxides selected from iron oxide, titanium oxide and cerium oxide, and metal hydroxides; a finely powdered silica selected from a precipitated silica or calcined silica, and/or a thixotropic improvement agent, wherein component is an organopolysiloxane represented by an average composition formula shown below: R 6 e SiO (4-e)/2 wherein, each R 6 represents, independently, an unsubstituted or substituted monovalent hydrocarbon group of 1 to 18 carbon atoms, and e represents a number from 1.8 to 2.2, with a kinematic viscosity at 25°C of 10 to 100,000 mm 2 /s, and component is a volatile solvent capable of dissolving or dispersing said components and, in a quantity not greater than 100 parts by volume per 100 parts by volume of said component wherein the component is toluene, xylene, acetone, methyl ethyl ketone, cyclohexanone, n-hexane, n-heptane, butanol, isopropanol, and isoparaffin-based solvents, or a combination thereof. wherein, each R 6 represents, independently, an unsubstituted or substituted monovalent hydrocarbon group of 1 to 18 carbon atoms, and e represents a number from 1.8 to 2.2, with a kinematic viscosity at 25°C of 10 to 100,000 mm 2 /s, and component is a volatile solvent capable of dissolving or dispersing said components and, in a quantity not greater than 100 parts by volume per 100 parts by volume of said component wherein the component is toluene, xylene, acetone, methyl ethyl ketone, cyclohexanone, n-hexane, n-heptane, butanol, isopropanol, and isoparaffin-based solvents, or a combination thereof.