A thermally-conductive organic additive comprising a liquid crystalline thermoplastic resin, not less than 50 mol% of the liquid crystalline thermoplastic resin having a chain structure, wherein not less than 50 mol% of the main chain of the liquid crystalline thermoplastic resin contains a repeating unit represented by the general formula: -M-Sp-... wherein M represents a mesogenic group; and Sp represents a spacer, the liquid crystalline thermoplastic resin per se having a thermal conductivity of not less than 0.45 W/(m·K), wherein not less than 50 mol% of the liquid crystalline thermoplastic resin contains a repeating unit represented by the general formula: -A 1 -x-A 2 -y-R-z-... wherein each of A 1 and A 2 independently represents a substituent group selected from an aromatic group, a condensed aromatic group, an alicyclic group, and an alicyclic heterocyclic group; each of x, y and z independently represents a direct bond, or a bivalent substituent group selected from the group consisting of -CH 2 -, -C(CH 3) 2 -, -O-, -S-, -CH 2 -CH 2 -, -CH=CH-, -C≡C-, -CO-, -CO-O-, -CO-NH-, -CH=N-, -CH=N-N=CH-, -N=N-, and -N =N-; and R represents a bivalent substituent group, R of the liquid crystalline thermoplastic resin is a linear aliphatic hydrocarbon chain, R of the liquid crystalline thermoplastic resin has a main chain length of 4 to 20 carbon atoms, and a number average molecular weight of the liquid crystalline thermoplastic resin is 3000 to 40000. wherein M represents a mesogenic group; and Sp represents a spacer, the liquid crystalline thermoplastic resin per se having a thermal conductivity of not less than 0.45 W/(m·K), wherein not less than 50 mol% of the liquid crystalline thermoplastic resin contains a repeating unit represented by the general formula: -A 1 -x-A 2 -y-R-z-... wherein each of A 1 and A 2 independently represents a substituent group selected from an aromatic group, a condensed aromatic group, an alicyclic group, and an alicyclic heterocyclic group; each of x, y and z independently represents a direct bond, or a bivalent substituent group selected from the group consisting of -CH 2 -, -C(CH 3) 2 -, -O-, -S-, -CH 2 -CH 2 -, -CH=CH-, -C≡C-, -CO-, -CO-O-, -CO-NH-, -CH=N-, -CH=N-N=CH-, -N=N-, and -N =N-; and R represents a bivalent substituent group, R of the liquid crystalline thermoplastic resin is a linear aliphatic hydrocarbon chain, R of the liquid crystalline thermoplastic resin has a main chain length of 4 to 20 carbon atoms, and a number average molecular weight of the liquid crystalline thermoplastic resin is 3000 to 40000. wherein each of A 1 and A 2 independently represents a substituent group selected from an aromatic group, a condensed aromatic group, an alicyclic group, and an alicyclic heterocyclic group; each of x, y and z independently represents a direct bond, or a bivalent substituent group selected from the group consisting of -CH 2 -, -C(CH 3) 2 -, -O-, -S-, -CH 2 -CH 2 -, -CH=CH-, -C≡C-, -CO-, -CO-O-, -CO-NH-, -CH=N-, -CH=N-N=CH-, -N=N-, and -N =N-; and R represents a bivalent substituent group, R of the liquid crystalline thermoplastic resin is a linear aliphatic hydrocarbon chain, R of the liquid crystalline thermoplastic resin has a main chain length of 4 to 20 carbon atoms, and a number average molecular weight of the liquid crystalline thermoplastic resin is 3000 to 40000.