【Objective】To determine the efficacy and safety of local injections of botulinum toxin A in the treatment of androgenetic alopecia.【Methods】72 male patients were randomly into botulinum toxin An group（n=35）and the control group（n=37），the treatment time was 6 months. All the patients were photographed and evaluated，before the treatment，and 3 months and 6 months.【Results】After the treatment of half a year，a good result was observed，the hair density in the treatment group was higher after 3months and 6 months than before the treatment（P<0.05），but there was no difference between the after 3months and 6 months（P>0.05），the hair density in the control group was higher after 6 months than before the treatment and after 3 months（P<0.05），but there was no difference between the after 3 months and before the treatment（P>0.05）；but there was no difference between the after 3 months and 6 months（P>0.05）； After 6 months，the effective ratio and in two group were 91.4% and 86.5% in treated group，it showed no significant difference（P>0.05）【Conclusion】the treatment of local injections of botulinum toxin A has a marked effect on androge? netic alopecia，it is safe and effective.