PURPOSE: To obtain a silicone composition capable of providing a cured product having high refractive index, excellent in transparency and suitable as an optical material to which heat resistance is required.

CONSTITUTION: This curable silicone composition for optical uses contains (A) a linear organopolysiloxane having vinyl groups at both ends and comprising methyl group and phenyl group as other organic group, (B) a branched organopolysiloxane copolymer composed of CH2=CH(CH3)2SiO0.5, (CH3)3SiO0.5, PhSiO1.5 (Ph is phenyl group) and SiO2 siloxane units and having 0.5-2.0 total molar ratio of total amount CH2=CH2(CH3)2SiO0.5 unit and (CH3)3SiO0.5 unit to SiO2 unit and containing ≥9mol% of total organic group bound to a silicon atom in the molecule as phenyl group, (C) an organohydrogenepolysiloxane having an organic group which is methyl group or phenyl group and having compatibility with the components A and B and (D) a platinum-based catalyst.