The present invention relates to a black dye composition, comprising: (a) a compound of the following formula (I), (b) a compound of the following formula (II), (c) a compound of the following formula (III), wherein R1, R2, R3, and R4 are defined the same as the specification. The present invention also relates to a black ink composition afforded from the aforementioned black dye composition. The black ink composition of the present invention is suitable for paper ink-jet printing, and exhibits the properties of good light-fastness, high color strength, solubility, and fine fluency of ink.