The present invention relates to a liquid formulation of long-acting insulinotropic peptide conjugate, comprising a pharmaceutically effective amount of long-acting insulinotropic peptide conjugate consisting of a physiologically active peptide, insulinotropic peptide, and an immunoglobulin Fc region； and an albumin-free stabilizer, wherein the stabilizer comprises a buffer, a sugar alcohol, a non-ionic surfactant, and an isotonic agent, and a method for preparing the formulation. For the purpose of preventing microbial contamination, a preservative may be added. The liquid formulation of the present invention is free of human serum albumin and other potentially hazardous factors to body, having no risk of viral contamination, and thus can provide excellent storage stability for insulinotropic peptide conjugates at high concentration.
