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 suppress the elasticity of the dermis and flatten out the depressed part of the scar and thus enables elaborate intradermic resection and increases the effects of lasers for treating blood vessels 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.
