Disclosed are: a disperse dye composition which is suitably applicable to synthetic textile materials to be used in the inside of an automobile, said synthetic textile material to be used therein being to be exposed to sunlight and/or high-temperature and high-humidity conditions, and which combines high light fastness and excellent dyeing characteristics; and a dyeing method using the same. The disperse dye composition comprises six specific disperse dyes (two specific disperse dyes per each of the three primary colors). The disperse dye composition and the dyeing method ensure both high light fastness and excellent dyeing characteristics, and achieve a reduction in dyeing temperature or dyeing time. This leads to huge energy savings.