Thermally conductive composition

A thermally conductive composition comprising a resin composition and a thermally conductive filler, wherein

• the resin composition comprises a vinyl group-containing silicone resin having a viscosity ranging from 40,000 mPa·s to 200,000,000 mPa·s at 25° C. as measured according to JIS Z8803:2011 and a polysiloxane compound having at least one hydroxy group at an end, having no vinyl group, and having a weight-average molecular weight (Mw) in terms of polystyrene of 10,000 or more and 20,000 or less as measured by gel permeation chromatography (GPC),
• the mass ratio of the vinyl group-containing silicone resin to the polysiloxane compound [the vinyl group-containing silicone resin/the polysiloxane compound] is 50/50 or more and less than 90/10,
• the content of the thermally conductive filler ranges from 300 parts by mass to 5,000 parts by mass with respect to 100 parts by mass of the resin composition, and
• a cured product of the thermally conductive composition has a thermal conductivity of 1.0 W/mk or more as measured according to ISO22007-2.