NOVELTY - Silicone resin composition (I) comprises: (A) organopolysiloxane (100 parts by mass) having a weight average molecular weight of 500-20000, reduced to polystyrene; (B) a white pigment (3-200 parts by mass); (C) an inorganic filler (400-1000 parts by mass) other than the white pigment; (D) a condensation catalyst (0.01-10 parts by mass); and (E) a organopolysiloxane (2-50 parts by mass) comprising a linear diorganopolysiloxane moiety.    USE - (I) is useful in optical semiconductor device (claimed), preferably reflectors. (I) is useful in pre-molded package for white, blue, and ultraviolet light emitting diodes, packaging material, and solar cells. (I) is useful for encapsulating general semiconductors or various modules in vehicles.    ADVANTAGE - (I) does not cause distortion in a device, when cured and provides a cured body which is white. (I) has good moldability and heat and light resistance, UV ray resistance. (I) has improved flowability.    DETAILED DESCRIPTION - Silicone resin composition (I) comprises: (A) organopolysiloxane (100 parts by mass) having a weight average molecular weight of 500-20000, reduced to polystyrene, where the organopolysiloxane has a structure of formula ((CH3)aSi(OR1)b(OH)cO(4-a-b-c)/2); (B) a white pigment (3-200 parts by mass); (C) an inorganic filler (400-1000 parts by mass) other than the white pigment; (D) a condensation catalyst (0.01-10 parts by mass); and (E) a organopolysiloxane (2-50 parts by mass) comprising a linear diorganopolysiloxane moiety having the structure of formula ((Si(R2)(R3)-(O))m).    R1 = 1-4C organic group;    a = 0.8-1.5;    b = 0-0.3;    c = 0.001-0.5, and a+b+c = 0.801-2;    R2, R3 = OH, 1-3C alkyl, cyclohexyl, vinyl, phenyl, or allyl; and    m = 5-50.    An INDEPENDENT CLAIM is included for an optical semiconductor device provided with the cured body of (I).    DESCRIPTION OF DRAWING(S) - The figure shows a cross sectional view of an optical semiconductor device.    Optical semiconductor element (1)    Lead frame (2)    Bonding wire (3)    Transparent encapsulating resin (4)    Reflector. (5)