The present invention discloses an electrolyte solution for an aluminum electrolytic capacitor and an aluminum electrolytic capacitor using the electrolyte solution. The electrolyte solution for an aluminum electrolytic capacitor, contains electrolyte (A) and an organic solvent (B); the electrolyte (A) contains electrolyte (C) and electrolyte (D); the electrolyte (C) consists of cations (E) and alkyl phosphate anions, and the electrolyte (D) consists of cations (F) and phthalic acid anions. The electrolyte solution of the present invention can obtain high specific conductivity and sparking voltage, and can realize aluminum electrolytic capacitor without a risk of corrosion of capacitor parts at the same time.