To provide a high-nickel plating bath which is weakly acidic and can stably form a plating film having a nickel content of 11 to 19% (preferably 12 to 18%) even at a current density of 3 A/dm2 or more. An acidic zinc-nickel alloy electroplating solution which contains an amine compound represented by the formula H2N—R1-R2 {wherein: R1 is [(CH2)M—NH]L or (CH2)N; R2 is H, NH2, or R3; R3 is an alkanol or alkoxyl group having 1, 2, 3, 4, or 5 carbon atoms; L is 2, 3, 4, or 5; M is 2, 3, 4, or 5; and N is 3, 4, or 5}.