THERMALLY CONDUCTIVE SILICONE COMPOSITION, AND THERMALLY CONDUCTIVE SILICONE SHEET

Provided is a thermally conductive silicone composition that can be turned into a lightweight cured product superior in thermal conductivity, and is easily processable due to its low viscosity. The composition contains:(A) an organopolysiloxane having at least two alkenyl groups per each molecule;(B) an organohydrogenpolysiloxane having, per each molecule, at least two hydrogen atoms directly bonded to silicon atoms;(C) a thermally conductive filler containing magnesium oxide, aluminum oxide and aluminum hydroxide;(D) a dimethylpolysiloxane with one end of the molecular chain thereof being blocked by a trialkoxy group;(E) a platinum group metal-based curing catalyst; and(F) an addition reaction control agent,wherein the thermally conductive filler as the component (C) is such that the magnesium oxide, aluminum oxide and aluminum hydroxide are respectively contained by an amount of 20 to 40% by mass, an amount of 40 to 60% by mass and an amount of 10 to 30% by mass, per the total amount of the component (C).