The present invention relates to a pharmaceutical composition for treating scars on the skin, comprising a mixture of botulinum toxin and air. The mixture of botulinum toxin and air according to the present invention, when injected in the dermis, may temporarily removed the elasticity of the dermis and flatten out the depressed part of the scar, and thus enables elaborate intradermic resection and increases the therapeutic effects of lasers for treating pulsed dye laser or of fractional lasers. Thus, scars on the skin can be effectively improved through a one-time operation without negatively affecting the daily lives of patients.
