The present invention relates to a liquid formulation containing a botulinum toxin and a stabilizing agent, and a preparation method therefor. A formulation technology containing botulinum toxin and a stabilizing agent, of the present invention, facilitates the storage and distribution of a liquid formulation and has shown a remarkable effect on the stabilization of botulinum toxin under conditions suitable for the human body's temperature and pH, thereby being expected to be widely used in the safe and convenient medical use of botulinum toxin.