NOVELTY - Curable silicone resin composition comprises (A) a silyloxy(silyloxysilyloxysilyloxy)silane compound (I) having at least two aliphatic unsaturated groups per one molecule, (B) an organic silicon compound having at least two hydrogen atoms bonded to silicon atom per one molecule and having no aliphatic unsaturated group, (C) a hydrosilylation catalyst containing a platinum group metal, and (D) 0.1-500 parts by mass of silicone powder having an average particle diameter of 0.5-100 mu m.    USE - The curable silicone resin composition, preferably an addition-curable silicone composition is useful: in a cured product; as a material for encapsulating a photosemiconductor device (all claimed) and an optical apparatus or optical parts; as an insulating material for an electronic apparatus or electronic parts; and as a coating material, where the photosemiconductor device includes LED device, emission device, semiconductor laser, a photodiode, a phototransistor, a solar battery and charge-coupled device.    ADVANTAGE - The composition has high reliability and heat resistance, and improves the light extraction efficiency, weather resistance, color fastness, transparency, tackiness, cold resistance, hardness and impact resistance of the photosemiconductor device.    DETAILED DESCRIPTION - Curable silicone resin composition comprises (A) a silyloxy(silyloxysilyloxysilyloxy)silane compound of formula (I) having at least two aliphatic unsaturated groups per one molecule, (B) an organic silicon compound having at least two hydrogen atoms bonded to silicon atom per one molecule and having no aliphatic unsaturated group, (C) a hydrosilylation catalyst containing a platinum group metal, and (D) 0.1-500 parts by mass of silicone powder having an average particle diameter of 0.5-100 mu m.    R1 = aliphatic unsaturated group;    R2 = 1-8C-monovalent hydrocarbyl (optionally substituted) other than aliphatic unsaturated group;    Rf1 = CF3-(CF2)m-(CH2)n-;    m, n = greater than or equal to 0;    a = 1-3;    x, z = 0; and    y = 1.