Objective : The purpose of this study is to analyze research trends on laser output used for treatment of hair loss. Methods : We searched papers using Pubmed, NDSL, KISS, and RISS. First search used the keyword "Laser, Alopecia" in Pubmed. Inclusion criteria were last 15 years, English, related to output. Finally we searched papers using the keyword "Laser and Alopecia" in NDSL, KISS, and RISS. Inclusion criteria were the same as first research except for English. Results : A total of 43 studies were found, 28 studies were excluded and 15 studies were selected and analyzed. And of the 15 studies, 7 studies were foreign papers and 8 studies were domestic papers on clinical application of laser status. Mainly Used type of laser was a diode laser. As a result, we found that treatment group had more improvement than control group. The range of the laser-output was 1mW-150W in Alopecia laser therapy. Conclusions : Low-level (LLLT) as well as High-level laser therapy (HLLT) can be effectively used as an alternative to the treatment of alopecia. Thus, further attention and studies are needed on this topic in order to reduce the side effects and demonstrate the effectiveness clearly.