To provide a silicone resin composition capable of affording an encapsulant stably maintaining electric insulating properties for a long period without corroding elements to be protected of a low cost and having excellent heat conductivity.

This heat conductive silicone resin composition is obtained by compounding 100 pts.mass of a silicone resin with 100-500 pts.mass of the mixed powder of two kinds of dott-like silver-plated spherical aluminum powders. The silicone resin is composed of (A) 100 pts.mass of an organopolysiloxane containing at least 2 silicon atom-bound alkenyl groups in one molecule, (B) 0.1-50 pts.mass of an organohydrogenpolysiloxane containing at least 2 silicon atom-bound hydrogen atoms in one molecule, (C) 0.1-10 pts.mass of an organopolysiloxane containing at least 1 silicon atom-bound alkoxy group or silicon atom-bound hydroxyl group in one molecule and (D) a catalyst for a hydrosilylating reaction in an amount of 0.1-500 ppm based on the organopolysiloxane. The mixed powder of the dott-like silver-plated spherical aluminum powders is prepared by plating the surface of an atomized aluminum powder with 1-10 mass% of silver into a dott-like state by a sputtering method and classifying the plated powder into two stages by varying the average particle diameter, and mixing them.