A solid dispersion comprising: an amorphous body composed of a heterocyclic compound represented by general formula: wherein, X represents a nitrogen atom or CH; R 1 and R 2, both or either one, a hydrogen atom, a hydroxyl group, a halogen, an amino group, a C 1 -C 6 alkylamino group, a C 1 -C 6 alkoxy group, a C 1 -C 6 alkyl group, or a cyano group; R 3 represents a hydrogen atom, a difluoromethyl group, an amino group, a C 1 -C 6 alkylamino group, a methyl, or a hydroxymethyl group; R 4 and R 5 represent a hydrogen atom or a C 1 -C 6 alkyl group; and R 6 represents a morpholino (optionally substituted with 1 to 2 C 1 -C 6 alkyl groups), a pyrrolidinyl (optionally substituted with a hydroxy C 1 -C 6 alkyl group), a piperidino (optionally substituted with 1 to 2 oxygen atoms, a hydroxyl group, a formyl, or a C 1 -C 6 alkyl group), a piperazinyl (optionally substituted with 1 to 2 oxygen atoms, the nitrogen at position 4 optionally substituted with a substituent selected from the group consisting of formyl, hydroxyl C 1 -C 6 alkyl, C 1 -C 6 alkoxycarbonyl, oxo C 1 -C 6 alkyl, aromatic carbonyl, benzylcarbonyl and substituted carbamoyl), or a 1,4-diazepano (optionally substituted with 1 to 2 oxygen atoms, the nitrogen at position 4 optionally substituted with a substituent selected from the group consisting of formyl, hydroxy C 1 -C 6 alkyl, C 1 -C 6 alkoxycarbonyl, oxo C 1 -C 6 alkyl, aromatic carbonyl, benzyl carbonyl and substituted carbamoyl); or a hydrate thereof, a solvate thereof, or a pharmaceutically acceptable salt thereof; and a solid polymer selected from hydroxypropyl cellulose and hypromellose, wherein the mass ratio of said heterocyclic compound, the hydrate thereof; the solvate thereof, or the pharmaceutically acceptable salt thereof and said solid polymer is 1:1 to 1:5. an amorphous body composed of a heterocyclic compound represented by general formula: wherein, X represents a nitrogen atom or CH; R 1 and R 2, both or either one, a hydrogen atom, a hydroxyl group, a halogen, an amino group, a C 1 -C 6 alkylamino group, a C 1 -C 6 alkoxy group, a C 1 -C 6 alkyl group, or a cyano group; R 3 represents a hydrogen atom, a difluoromethyl group, an amino group, a C 1 -C 6 alkylamino group, a methyl, or a hydroxymethyl group; R 4 and R 5 represent a hydrogen atom or a C 1 -C 6 alkyl group; and R 6 represents a morpholino (optionally substituted with 1 to 2 C 1 -C 6 alkyl groups), a pyrrolidinyl (optionally substituted with a hydroxy C 1 -C 6 alkyl group), a piperidino (optionally substituted with 1 to 2 oxygen atoms, a hydroxyl group, a formyl, or a C 1 -C 6 alkyl group), a piperazinyl (optionally substituted with 1 to 2 oxygen atoms, the nitrogen at position 4 optionally substituted with a substituent selected from the group consisting of formyl, hydroxyl C 1 -C 6 alkyl, C 1 -C 6 alkoxycarbonyl, oxo C 1 -C 6 alkyl, aromatic carbonyl, benzylcarbonyl and substituted carbamoyl), or a 1,4-diazepano (optionally substituted with 1 to 2 oxygen atoms, the nitrogen at position 4 optionally substituted with a substituent selected from the group consisting of formyl, hydroxy C 1 -C 6 alkyl, C 1 -C 6 alkoxycarbonyl, oxo C 1 -C 6 alkyl, aromatic carbonyl, benzyl carbonyl and substituted carbamoyl); or a hydrate thereof, a solvate thereof, or a pharmaceutically acceptable salt thereof; and wherein, X represents a nitrogen atom or CH; R 1 and R 2, both or either one, a hydrogen atom, a hydroxyl group, a halogen, an amino group, a C 1 -C 6 alkylamino group, a C 1 -C 6 alkoxy group, a C 1 -C 6 alkyl group, or a cyano group; R 3 represents a hydrogen atom, a difluoromethyl group, an amino group, a C 1 -C 6 alkylamino group, a methyl, or a hydroxymethyl group; R 4 and R 5 represent a hydrogen atom or a C 1 -C 6 alkyl group; and R 6 represents a morpholino (optionally substituted with 1 to 2 C 1 -C 6 alkyl groups), a pyrrolidinyl (optionally substituted with a hydroxy C 1 -C 6 alkyl group), a piperidino (optionally substituted with 1 to 2 oxygen atoms, a hydroxyl group, a formyl, or a C 1 -C 6 alkyl group), a piperazinyl (optionally substituted with 1 to 2 oxygen atoms, the nitrogen at position 4 optionally substituted with a substituent selected from the group consisting of formyl, hydroxyl C 1 -C 6 alkyl, C 1 -C 6 alkoxycarbonyl, oxo C 1 -C 6 alkyl, aromatic carbonyl, benzylcarbonyl and substituted carbamoyl), or a 1,4-diazepano (optionally substituted with 1 to 2 oxygen atoms, the nitrogen at position 4 optionally substituted with a substituent selected from the group consisting of formyl, hydroxy C 1 -C 6 alkyl, C 1 -C 6 alkoxycarbonyl, oxo C 1 -C 6 alkyl, aromatic carbonyl, benzyl carbonyl and substituted carbamoyl); or a hydrate thereof, a solvate thereof, or a pharmaceutically acceptable salt thereof; and a solid polymer selected from hydroxypropyl cellulose and hypromellose, wherein the mass ratio of said heterocyclic compound, the hydrate thereof; the solvate thereof, or the pharmaceutically acceptable salt thereof and said solid polymer is 1:1 to 1:5.