An insulin conjugate using an immunoglobulin fragment

The present invention relates to an insulin conjugate having improved in vivo duration and stability, which is prepared by covalently linking insulin with an immunoglobulin Fc region via a non-peptidyl polymer, a long-acting formulation comprising the same, and a preparation method thereof. The insulin conjugate of the present invention maintains in vivo activity of the peptide at a relatively high level and remarkably increases the serum half-life thereof, thereby greatly improving drug compliance upon insulin treatment.