To provide a silicone composition which does not adhere on a set material mainly including silicone, such as a silicone impression material used in the dental operation field, when being built on the set material mainly including silicone, the silicone composition includes (A) 100 weight parts of organopolysiloxane having at least two aliphatic unsaturated hydrocarbons in one molecule, (B) 0.1 to 50 weight parts of organohydrogenpolysiloxane having at least three hydrogen atoms, which directly bond to a silicon atom, in one molecule and including SiO.sub.2 units, (C) 0.1 to 50 weight parts of fine silica powder having a BET specific surface area of 50 to 500 m.sup.2/g and being subjected to a hydrophobic treatment on the surface thereof, and 10 to 800 ppm of a silicone-soluble platinum compound with respect to 100 weight parts of the total of the (A) and (B) components.